Check node js version windows

Knowing what Node.jsNode.js is an asynchronous event-driven JavaScript runtime and is the most effective when building scalable network applications. Node.js is free of locks, so there’s no chance to dead-lock any process. version you have in a project is vital because it affects the Node and JavaScript language features you can use. Also, you might not want to miss out on essential security patches or experience compatibility problems.

There are several ways to check the Node version you’re using. You can use basic command line prompts, npmnpm is a software registry that serves over 1.3 million packages. npm is used by open source developers from all around the world to share and borrow code, as well as many businesses. There are three components to npm: the website the Command Line Interface (CLI) the registry Use the website to discover and download packages, create user profiles, and…, or nvm as well to do it. In this article below, we list ways for you to check your Node version with different methods, on different operating systems.

Check your Node version in one step

To check the version of Node.js on your computer (may it run MacOS, Windows or a Linux distro such as Ubuntu), run the following command:

$ node -v

This will return the current version of node that is installed on your system. 

If you want to learn more about Node.js, you can find instructions and official docs on the node website. https://nodejs.org/en/download/ 

To check the latest version of Node for both the LTSLTS means long-term support. The acronym is often used to mark Node.js release lines that will be maintained and supported for an extended period. There are two separate kinds of LTS releases: Active and Maintenance. The Active release line often gets new features and other improvements beside security patches and bug fixes, and the Maintenance only gets the latter. It… and Current versions, check out our blog post that collects and lists all major updates.

Using npm to check your node version (and also update it)

Alternatively, you can use a package manager like npm to update Node. 

https://docs.npmjs.com/cli/update-node

$ npm install -g npm@latest 

then

$ npm update -g node 

will update node and npm. 

If you are having issues with your node installation, you can try the following commands:

$ npm cache clean

$ npm install -g --unsafe-perm node 

These commands will try to clean up any issues with your npm cache and install Node with permissions that may help resolve any installation issues. 

To only check your npm version, you can use the following command:

$ npm -v

Managing your Node versions with nvm

NVM (Node Version Manager) is a bash script that allows you to manage multiple active versions of Node.js. It allows you to install, uninstall, list, and switch between node versions.

​​The preferred way for managing your local node.js versions is to use nvm, which can be installed like this:

curl https://raw.githubusercontent.com/creationix/nvm/v0.33.3/install.sh | bash

Then, use this to install node.js:

$ nvm install node

To use a specific version of node.js, you can do:

$ nvm use node

If you want to uninstall node.js, you can type:

$ nvm uninstall node

To update Node to the latest LTS version, you can use the nvm update node command.

For further details on how to install specific versions, see the nvm docs: https://github.com/nvm-sh/nvm

If you’re using Windows, you’ll need to use nvm-windows, which has almost the same API as nvm, but is a completely different project, and has a different philosophy. https://github.com/coreybutler/nvm-windows

What is Node.js?

If you are already familiar with Node, but need a quick refresher about it, we’ve got you covered:

Node.js is a platform built on Chrome’s JavaScript runtime for easily building fast, scalable network applications. It uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices. 

Node.js is open-source and free to use. It also provides a first-class development experience, making it an ideal platform for web-based applications. Node.js also has a large community of developers who are constantly creating new modules and libraries to make development easier. 

Node.js applications are written in JavaScript, and can be run on Mac OS X, Windows, and Linux which makes it fully cross-platform. Node.js has an event-driven architecture and a non-blocking I/O model that makes it lightweight and efficient. These features make it perfect for data-intensive, real-time applications that run across distributed devices. 

There are a few things to keep in mind when writing Node.js applications. First, since Node.js is asynchronous, you need to use promises, asyncAsynchrony, in software programming, refers to events that occur outside of the primary program flow and methods for dealing with them. External events such as signals or activities prompted by a program that occur at the same time as program execution without causing the program to block and wait for results are examples of this category. Asynchronous input/output is an… functions, callbacks or events to handle data flow. Second, Node.js is single-threaded, so you need to be careful not to block the thread with long computations. 

How the Node release schedule works

A few words about the Node.js release schedule:

Releases

The Node.js Release Schedule

Node.js releases are identified by a major and minor version number, e.g. v4.2.0. Minor version releases (e.g. v4.2.1) are made every few weeks and contain new features and bug fixes. Major version releases (e.g. v5.0.0) are made every six months or so and may contain breaking changes.

Nowadays, the LTS (long-term support) Node.js versions get an even number, like 16.14.0, while Current releases have an odd version number, like 17.5.0.

In the dynamic world of web development, Node.js plays a critical role in building powerful applications that can handle increasing demands. Whether you’re a seasoned coder or just starting out, knowing how to check Node.js version is an essential skill.

Why is this important? Node.js is constantly evolving, with each new release bringing exciting features, bug fixes, and performance improvements. Understanding your current Node.js version ensures you can leverage its full potential and maintain compatibility with your projects. This guide will equip you with the knowledge to easily check Node.js version, putting you in control of your development environment.

What is Node.js?

Node.js, a popular open-source runtime environment, empowers developers to run JavaScript code beyond the confines of web browsers. Built upon Chrome’s V8 JavaScript engine, Node.js was first brought to life by Ryan Dahl in 2009. Since then, it’s become a mainstay in web development, offering unique capabilities.

The key advantage of Node.js lies in its ability to execute JavaScript code on the server-side, not just on the client-side (the browser). This unlocks a new frontier for developers: building dynamic and data-driven applications that interact seamlessly with servers. Node.js is particularly admired for its non-blocking, event-driven architecture, which contributes to its efficiency and lightweight nature.

check node.js version

How to Check Node.js Version In Some Easy Steps

There are several ways to determine your Node.js version. Let’s explore these methods to ensure you’re always working with the right version for your needs.

Using the Command Line

One of the simplest methods is to open your command prompt (Windows), terminal (Mac/Linux), and run the following command:

node -v

This command will display the installed Node.js version on your system.

Checking from Within JavaScript Code

If you’d like to check the Node.js version from within a JavaScript file, here are two approaches:

1. Using process.version:

JavaScript

console.log(process.version);

This code snippet will print the Node.js version to the console when you run the JavaScript file.

2. Using process.versions:

JavaScript

onsole.log(process.versions.node);

This approach provides more detailed information specifically about the Node.js version.

check node.js version

Checking from Package.json (For Projects)

When working on a Node.js project, you can check the required Node.js version specified in the project’s package.json file. Look for the “engines” field, which defines the compatible Node.js versions.

For example:

JSON

“engines”: {

  “node”: “>=12.0.0”

}

This example indicates that the project requires Node.js version 12.0.0 or higher.

Using Node Version Managers (NVMs)

A strong tool for managing several Node.js versions on your machine is Node Version Manager (NVM). With NVM, you can easily switch between Node.js versions depending on the requirements of your different projects. While not covered here, consider exploring NVM for more advanced version management.

How to Check Your Node.js Version on Different Operating Systems

Knowing your Node.js version is crucial for ensuring compatibility with your projects. Here’s a quick guide to checking it on various operating systems:

Linux:

1. Open your Terminal: Most Linux distributions provide a built-in terminal application. You can usually find it in your Applications list or access it using a keyboard shortcut (like Ctrl+Alt+T).

2. Check Installed Version: Once the terminal is open, simply type node -v and press Enter. This command will display the current Node.js version running on your system.

3. Verify npm Version (Optional): If you also want to confirm the installed version of npm (Node Package Manager), type npm -v and press Enter. This will show the npm version alongside the Node.js version.

Windows:

For Windows users, checking the Node.js version is equally straightforward:

1. Open Command Prompt/PowerShell: Launch either the Command Prompt or PowerShell application. You can find them by searching for them in the Windows search bar.

2. Run the Version Check: Once your chosen application is open, type node -v and press Enter. This command will display the installed Node.js version on your Windows machine.

3. Optional npm Check: Similar to Linux, you can verify the npm version using npm -v. This command will reveal the currently installed npm version.

check node.js version

Mac:

Mac users have a similarly easy process for checking Node.js versions:

1. Launch Terminal: Locate the Terminal application within the “Utilities” folder inside your “Applications” directory.

2. Execute the Version Command: Once you have Terminal open, type node -v and press Enter. This command will promptly display the version of Node.js installed on your Mac.

3. Optional npm Verification: If you’d also like to confirm the npm version, type npm -v and press Enter. This will display the version of npm installed on your macOS system.

By following these simple steps, you can easily check your Node.js version on any of these popular operating systems.

Troubleshooting Common Issues with Checking Node.js Version

Even though checking your Node.js version is a straightforward process, occasional challenges can arise. Here’s how to address some typical problems:

  • Version Not Found: If you see a “command not found” error when trying to check the version, it might be a system PATH issue. Verify that Node.js is installed correctly and its directory is included in your PATH environment variable.
  • Outdated Version: If your Node.js version is older and needs updating, consider using a version manager like NVM. This allows you to switch to a newer version easily without affecting other projects.
  • Permission Denied: On Linux and macOS, you might encounter “Permission Denied” errors when installing or updating Node.js with npm. To resolve this, use a package manager like nvm or run the command with administrator privileges (using sudo on Linux/macOS).
  • Conflicting Versions:Be mindful of multiple Node.js versions on your system. If your application uses the wrong version, it could lead to compatibility problems. Always ensure you’re using the version your project requires.
  • Package Compatibility Issues:After updating Node.js, some packages and dependencies in your project might become incompatible. You may need to update or modify these packages to ensure they work with the new Node.js version.
  • Cross-Platform Development Considerations:If you develop for multiple platforms, different operating systems might have different Node.js versions installed. It’s crucial to keep your projects and dependencies consistent across all platforms.
  • Global vs. Local Installations:js can be installed globally or locally within a project. Understand the differences and choose the appropriate method based on your project’s needs.

By following these tips, you can troubleshoot common issues and ensure a smooth experience when checking your Node.js version.

Conclusion

In today’s dynamic world of web development, using the most recent tools and technologies is essential. Node.js, with its adaptability and thriving community, exemplifies this perfectly. Knowing your Node.js version is a vital step to ensure you’re reaping all the benefits of this runtime environment.

By keeping your Node.js version current, you’re not just gaining access to bug fixes and performance improvements, but you’re also guaranteeing that your applications and projects work seamlessly with the latest features. This proactive strategy can save you valuable time and effort down the line, preventing compatibility roadblocks and promoting a smooth development process.

Ready to Streamline Your Workflow? Knowing your Node.js version is just the first step. ONextDigital’s CRM & Auto Marketing Automation Solution can seamlessly integrate with your Node.js application, automating tasks and boosting your development efficiency. Focus on what you do best – building innovative applications – and leave the rest to us. Contact us now!

Node.js comes with a variety of CLI options. These options expose built-in
debugging, multiple ways to execute scripts, and other helpful runtime options.

To view this documentation as a manual page in a terminal, run man node.

Synopsis#

node [options] [V8 options] [<program-entry-point> | -e "script" | -] [--] [arguments]

node inspect [<program-entry-point> | -e "script" | <host>:<port>] …

node --v8-options

Execute without arguments to start the REPL.

For more info about node inspect, see the debugger documentation.

Program entry point#

The program entry point is a specifier-like string. If the string is not an
absolute path, it’s resolved as a relative path from the current working
directory. That path is then resolved by CommonJS module loader. If no
corresponding file is found, an error is thrown.

If a file is found, its path will be passed to the
ES module loader under any of the following conditions:

  • The program was started with a command-line flag that forces the entry
    point to be loaded with ECMAScript module loader, such as --import.
  • The file has an .mjs extension.
  • The file does not have a .cjs extension, and the nearest parent
    package.json file contains a top-level "type" field with a value of
    "module".

Otherwise, the file is loaded using the CommonJS module loader. See
Modules loaders for more details.

ECMAScript modules loader entry point caveat#

When loading, the ES module loader loads the program
entry point, the node command will accept as input only files with .js,
.mjs, or .cjs extensions. With the following flags, additional file
extensions are enabled:

  • --experimental-wasm-modules for files with .wasm extension.
  • --experimental-addon-modules for files with .node extension.

Options#

All options, including V8 options, allow words to be separated by both
dashes (-) or underscores (_). For example, --pending-deprecation is
equivalent to --pending_deprecation.

If an option that takes a single value (such as --max-http-header-size) is
passed more than once, then the last passed value is used. Options from the
command line take precedence over options passed through the NODE_OPTIONS
environment variable.

-#

Added in: v8.0.0

Alias for stdin. Analogous to the use of - in other command-line utilities,
meaning that the script is read from stdin, and the rest of the options
are passed to that script.

--#

Added in: v6.11.0

Indicate the end of node options. Pass the rest of the arguments to the script.
If no script filename or eval/print script is supplied prior to this, then
the next argument is used as a script filename.

--abort-on-uncaught-exception#

Added in: v0.10.8

Aborting instead of exiting causes a core file to be generated for post-mortem
analysis using a debugger (such as lldb, gdb, and mdb).

If this flag is passed, the behavior can still be set to not abort through
process.setUncaughtExceptionCaptureCallback() (and through usage of the
node:domain module that uses it).

--allow-addons#

Added in: v21.6.0, v20.12.0

When using the Permission Model, the process will not be able to use
native addons by default.
Attempts to do so will throw an ERR_DLOPEN_DISABLED unless the
user explicitly passes the --allow-addons flag when starting Node.js.

Example:

// Attempt to require an native addon
require('nodejs-addon-example'); 
$ node --permission --allow-fs-read=* index.js
node:internal/modules/cjs/loader:1319
  return process.dlopen(module, path.toNamespacedPath(filename));
                 ^

Error: Cannot load native addon because loading addons is disabled.
    at Module._extensions..node (node:internal/modules/cjs/loader:1319:18)
    at Module.load (node:internal/modules/cjs/loader:1091:32)
    at Module._load (node:internal/modules/cjs/loader:938:12)
    at Module.require (node:internal/modules/cjs/loader:1115:19)
    at require (node:internal/modules/helpers:130:18)
    at Object.<anonymous> (/home/index.js:1:15)
    at Module._compile (node:internal/modules/cjs/loader:1233:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1287:10)
    at Module.load (node:internal/modules/cjs/loader:1091:32)
    at Module._load (node:internal/modules/cjs/loader:938:12) {
  code: 'ERR_DLOPEN_DISABLED'
} 

--allow-child-process#

Added in: v20.0.0

When using the Permission Model, the process will not be able to spawn any
child process by default.
Attempts to do so will throw an ERR_ACCESS_DENIED unless the
user explicitly passes the --allow-child-process flag when starting Node.js.

Example:

const childProcess = require('node:child_process');
// Attempt to bypass the permission
childProcess.spawn('node', ['-e', 'require("fs").writeFileSync("/new-file", "example")']); 
$ node --permission --allow-fs-read=* index.js
node:internal/child_process:388
  const err = this._handle.spawn(options);
                           ^
Error: Access to this API has been restricted
    at ChildProcess.spawn (node:internal/child_process:388:28)
    at node:internal/main/run_main_module:17:47 {
  code: 'ERR_ACCESS_DENIED',
  permission: 'ChildProcess'
} 

Unlike child_process.spawn, the child_process.fork API copies the execution
arguments from the parent process. This means that if you start Node.js with the
Permission Model enabled and include the --allow-child-process flag, calling
child_process.fork() will propagate all Permission Model flags to the child
process.

--allow-fs-read#

This flag configures file system read permissions using
the Permission Model.

The valid arguments for the --allow-fs-read flag are:

  • * — To allow all FileSystemRead operations.
  • Multiple paths can be allowed using multiple --allow-fs-read flags.
    Example --allow-fs-read=/folder1/ --allow-fs-read=/folder1/

Examples can be found in the File System Permissions documentation.

The initializer module also needs to be allowed. Consider the following example:

$ node --permission index.js

Error: Access to this API has been restricted
    at node:internal/main/run_main_module:23:47 {
  code: 'ERR_ACCESS_DENIED',
  permission: 'FileSystemRead',
  resource: '/Users/rafaelgss/repos/os/node/index.js'
} 

The process needs to have access to the index.js module:

node --permission --allow-fs-read=/path/to/index.js index.js 

--allow-fs-write#

This flag configures file system write permissions using
the Permission Model.

The valid arguments for the --allow-fs-write flag are:

  • * — To allow all FileSystemWrite operations.
  • Multiple paths can be allowed using multiple --allow-fs-write flags.
    Example --allow-fs-write=/folder1/ --allow-fs-write=/folder1/

Paths delimited by comma (,) are no longer allowed.
When passing a single flag with a comma a warning will be displayed.

Examples can be found in the File System Permissions documentation.

--allow-wasi#

Added in: v22.3.0, v20.16.0

When using the Permission Model, the process will not be capable of creating
any WASI instances by default.
For security reasons, the call will throw an ERR_ACCESS_DENIED unless the
user explicitly passes the flag --allow-wasi in the main Node.js process.

Example:

const { WASI } = require('node:wasi');
// Attempt to bypass the permission
new WASI({
  version: 'preview1',
  // Attempt to mount the whole filesystem
  preopens: {
    '/': '/',
  },
}); 
$ node --permission --allow-fs-read=* index.js

Error: Access to this API has been restricted
    at node:internal/main/run_main_module:30:49 {
  code: 'ERR_ACCESS_DENIED',
  permission: 'WASI',
} 

--allow-worker#

Added in: v20.0.0

When using the Permission Model, the process will not be able to create any
worker threads by default.
For security reasons, the call will throw an ERR_ACCESS_DENIED unless the
user explicitly pass the flag --allow-worker in the main Node.js process.

Example:

const { Worker } = require('node:worker_threads');
// Attempt to bypass the permission
new Worker(__filename); 
$ node --permission --allow-fs-read=* index.js

Error: Access to this API has been restricted
    at node:internal/main/run_main_module:17:47 {
  code: 'ERR_ACCESS_DENIED',
  permission: 'WorkerThreads'
} 

--build-snapshot#

Added in: v18.8.0

Generates a snapshot blob when the process exits and writes it to
disk, which can be loaded later with --snapshot-blob.

When building the snapshot, if --snapshot-blob is not specified,
the generated blob will be written, by default, to snapshot.blob
in the current working directory. Otherwise it will be written to
the path specified by --snapshot-blob.

$ echo "globalThis.foo = 'I am from the snapshot'" > snapshot.js

# Run snapshot.js to initialize the application and snapshot the
# state of it into snapshot.blob.
$ node --snapshot-blob snapshot.blob --build-snapshot snapshot.js

$ echo "console.log(globalThis.foo)" > index.js

# Load the generated snapshot and start the application from index.js.
$ node --snapshot-blob snapshot.blob index.js
I am from the snapshot 

The v8.startupSnapshot API can be used to specify an entry point at
snapshot building time, thus avoiding the need of an additional entry
script at deserialization time:

$ echo "require('v8').startupSnapshot.setDeserializeMainFunction(() => console.log('I am from the snapshot'))" > snapshot.js
$ node --snapshot-blob snapshot.blob --build-snapshot snapshot.js
$ node --snapshot-blob snapshot.blob
I am from the snapshot 

For more information, check out the v8.startupSnapshot API documentation.

Currently the support for run-time snapshot is experimental in that:

  1. User-land modules are not yet supported in the snapshot, so only
    one single file can be snapshotted. Users can bundle their applications
    into a single script with their bundler of choice before building
    a snapshot, however.
  2. Only a subset of the built-in modules work in the snapshot, though the
    Node.js core test suite checks that a few fairly complex applications
    can be snapshotted. Support for more modules are being added. If any
    crashes or buggy behaviors occur when building a snapshot, please file
    a report in the Node.js issue tracker and link to it in the
    tracking issue for user-land snapshots.

--build-snapshot-config#

Added in: v21.6.0, v20.12.0

Specifies the path to a JSON configuration file which configures snapshot
creation behavior.

The following options are currently supported:

  • builder <string> Required. Provides the name to the script that is executed
    before building the snapshot, as if --build-snapshot had been passed
    with builder as the main script name.
  • withoutCodeCache <boolean> Optional. Including the code cache reduces the
    time spent on compiling functions included in the snapshot at the expense
    of a bigger snapshot size and potentially breaking portability of the
    snapshot.

When using this flag, additional script files provided on the command line will
not be executed and instead be interpreted as regular command line arguments.

-c, --check#

Syntax check the script without executing.

--completion-bash#

Added in: v10.12.0

Print source-able bash completion script for Node.js.

node --completion-bash > node_bash_completion
source node_bash_completion 

-C condition, --conditions=condition#

Provide custom conditional exports resolution conditions.

Any number of custom string condition names are permitted.

The default Node.js conditions of "node", "default", "import", and
"require" will always apply as defined.

For example, to run a module with «development» resolutions:

node -C development app.js 

--cpu-prof#

Starts the V8 CPU profiler on start up, and writes the CPU profile to disk
before exit.

If --cpu-prof-dir is not specified, the generated profile is placed
in the current working directory.

If --cpu-prof-name is not specified, the generated profile is
named CPU.${yyyymmdd}.${hhmmss}.${pid}.${tid}.${seq}.cpuprofile.

$ node --cpu-prof index.js
$ ls *.cpuprofile
CPU.20190409.202950.15293.0.0.cpuprofile 

If --cpu-prof-name is specified, the provided value will be used as-is; patterns such as
${hhmmss} or ${pid} are not supported.

$ node --cpu-prof --cpu-prof-name 'CPU.${pid}.cpuprofile' index.js
$ ls *.cpuprofile
'CPU.${pid}.cpuprofile' 

--cpu-prof-dir#

Specify the directory where the CPU profiles generated by --cpu-prof will
be placed.

The default value is controlled by the
--diagnostic-dir command-line option.

--cpu-prof-interval#

Specify the sampling interval in microseconds for the CPU profiles generated
by --cpu-prof. The default is 1000 microseconds.

--cpu-prof-name#

Specify the file name of the CPU profile generated by --cpu-prof.

--diagnostic-dir=directory#

Set the directory to which all diagnostic output files are written.
Defaults to current working directory.

Affects the default output directory of:

  • --cpu-prof-dir
  • --heap-prof-dir
  • --redirect-warnings

--disable-proto=mode#

Added in: v13.12.0, v12.17.0

Disable the Object.prototype.__proto__ property. If mode is delete, the
property is removed entirely. If mode is throw, accesses to the
property throw an exception with the code ERR_PROTO_ACCESS.

--disable-sigusr1#

Added in: v23.7.0

Disable the ability of starting a debugging session by sending a
SIGUSR1 signal to the process.

--disable-warning=code-or-type#

Added in: v21.3.0, v20.11.0

Disable specific process warnings by code or type.

Warnings emitted from process.emitWarning() may contain a
code and a type. This option will not-emit warnings that have a matching
code or type.

List of deprecation warnings.

The Node.js core warning types are: DeprecationWarning and
ExperimentalWarning

For example, the following script will not emit
DEP0025 require('node:sys') when executed with
node --disable-warning=DEP0025:

import sys from 'node:sys';const sys = require('node:sys');

For example, the following script will emit the
DEP0025 require('node:sys'), but not any Experimental
Warnings (such as
ExperimentalWarning: vm.measureMemory is an experimental feature
in <=v21) when executed with node --disable-warning=ExperimentalWarning:

import sys from 'node:sys';
import vm from 'node:vm';

vm.measureMemory();const sys = require('node:sys');
const vm = require('node:vm');

vm.measureMemory();

--disable-wasm-trap-handler#

Added in: v22.2.0, v20.15.0

By default, Node.js enables trap-handler-based WebAssembly bound
checks. As a result, V8 does not need to insert inline bound checks
int the code compiled from WebAssembly which may speedup WebAssembly
execution significantly, but this optimization requires allocating
a big virtual memory cage (currently 10GB). If the Node.js process
does not have access to a large enough virtual memory address space
due to system configurations or hardware limitations, users won’t
be able to run any WebAssembly that involves allocation in this
virtual memory cage and will see an out-of-memory error.

$ ulimit -v 5000000
$ node -p "new WebAssembly.Memory({ initial: 10, maximum: 100 });"
[eval]:1
new WebAssembly.Memory({ initial: 10, maximum: 100 });
^

RangeError: WebAssembly.Memory(): could not allocate memory
    at [eval]:1:1
    at runScriptInThisContext (node:internal/vm:209:10)
    at node:internal/process/execution:118:14
    at [eval]-wrapper:6:24
    at runScript (node:internal/process/execution:101:62)
    at evalScript (node:internal/process/execution:136:3)
    at node:internal/main/eval_string:49:3
 

--disable-wasm-trap-handler disables this optimization so that
users can at least run WebAssembly (with less optimal performance)
when the virtual memory address space available to their Node.js
process is lower than what the V8 WebAssembly memory cage needs.

--disallow-code-generation-from-strings#

Added in: v9.8.0

Make built-in language features like eval and new Function that generate
code from strings throw an exception instead. This does not affect the Node.js
node:vm module.

--dns-result-order=order#

Set the default value of order in dns.lookup() and
dnsPromises.lookup(). The value could be:

  • ipv4first: sets default order to ipv4first.
  • ipv6first: sets default order to ipv6first.
  • verbatim: sets default order to verbatim.

The default is verbatim and dns.setDefaultResultOrder() have higher
priority than --dns-result-order.

--enable-fips#

Added in: v6.0.0

Enable FIPS-compliant crypto at startup. (Requires Node.js to be built
against FIPS-compatible OpenSSL.)

--enable-network-family-autoselection#

Added in: v18.18.0

Enables the family autoselection algorithm unless connection options explicitly
disables it.

--enable-source-maps#

Enable Source Map v3 support for stack traces.

When using a transpiler, such as TypeScript, stack traces thrown by an
application reference the transpiled code, not the original source position.
--enable-source-maps enables caching of Source Maps and makes a best
effort to report stack traces relative to the original source file.

Overriding Error.prepareStackTrace may prevent --enable-source-maps from
modifying the stack trace. Call and return the results of the original
Error.prepareStackTrace in the overriding function to modify the stack trace
with source maps.

const originalPrepareStackTrace = Error.prepareStackTrace;
Error.prepareStackTrace = (error, trace) => {
  // Modify error and trace and format stack trace with
  // original Error.prepareStackTrace.
  return originalPrepareStackTrace(error, trace);
}; 

Note, enabling source maps can introduce latency to your application
when Error.stack is accessed. If you access Error.stack frequently
in your application, take into account the performance implications
of --enable-source-maps.

--entry-url#

Added in: v23.0.0

When present, Node.js will interpret the entry point as a URL, rather than a
path.

Follows ECMAScript module resolution rules.

Any query parameter or hash in the URL will be accessible via import.meta.url.

node --entry-url 'file:///path/to/file.js?queryparams=work#and-hashes-too'
node --entry-url 'file.ts?query#hash'
node --entry-url 'data:text/javascript,console.log("Hello")' 

--env-file-if-exists=config#

Added in: v22.9.0

Behavior is the same as --env-file, but an error is not thrown if the file
does not exist.

--env-file=config#

Loads environment variables from a file relative to the current directory,
making them available to applications on process.env. The environment
variables which configure Node.js, such as NODE_OPTIONS,
are parsed and applied. If the same variable is defined in the environment and
in the file, the value from the environment takes precedence.

You can pass multiple --env-file arguments. Subsequent files override
pre-existing variables defined in previous files.

An error is thrown if the file does not exist.

node --env-file=.env --env-file=.development.env index.js 

The format of the file should be one line per key-value pair of environment
variable name and value separated by =:

PORT=3000 

Any text after a # is treated as a comment:

# This is a comment
PORT=3000 # This is also a comment 

Values can start and end with the following quotes: `, " or '.
They are omitted from the values.

USERNAME="nodejs" # will result in `nodejs` as the value. 

Multi-line values are supported:

MULTI_LINE="THIS IS
A MULTILINE"
# will result in `THIS IS\nA MULTILINE` as the value. 

Export keyword before a key is ignored:

export USERNAME="nodejs" # will result in `nodejs` as the value. 

If you want to load environment variables from a file that may not exist, you
can use the --env-file-if-exists flag instead.

-e, --eval "script"#

Evaluate the following argument as JavaScript. The modules which are
predefined in the REPL can also be used in script.

On Windows, using cmd.exe a single quote will not work correctly because it
only recognizes double " for quoting. In Powershell or Git bash, both '
and " are usable.

It is possible to run code containing inline types unless the
--no-experimental-strip-types flag is provided.

--experimental-addon-modules#

Added in: v23.6.0

Enable experimental import support for .node addons.

--experimental-async-context-frame#

Added in: v22.7.0

Enables the use of AsyncLocalStorage backed by AsyncContextFrame rather
than the default implementation which relies on async_hooks. This new model is
implemented very differently and so could have differences in how context data
flows within the application. As such, it is presently recommended to be sure
your application behaviour is unaffected by this change before using it in
production.

--experimental-config-file=config#

Added in: v23.10.0

If present, Node.js will look for a configuration file at the specified path.
Node.js will read the configuration file and apply the settings. The
configuration file should be a JSON file with the following structure. vX.Y.Z
in the $schema must be replaced with the version of Node.js you are using.

{
  "$schema": "https://nodejs.org/dist/vX.Y.Z/docs/node-config-schema.json",
  "nodeOptions": {
    "import": [
      "amaro/strip"
    ],
    "watch-path": "src",
    "watch-preserve-output": true
  }
} 

In the nodeOptions field, only flags that are allowed in NODE_OPTIONS are supported.
No-op flags are not supported.
Not all V8 flags are currently supported.

It is possible to use the official JSON schema
to validate the configuration file, which may vary depending on the Node.js version.
Each key in the configuration file corresponds to a flag that can be passed
as a command-line argument. The value of the key is the value that would be
passed to the flag.

For example, the configuration file above is equivalent to
the following command-line arguments:

node --import amaro/strip --watch-path=src --watch-preserve-output 

The priority in configuration is as follows:

  1. NODE_OPTIONS and command-line options
  2. Configuration file
  3. Dotenv NODE_OPTIONS

Values in the configuration file will not override the values in the environment
variables and command-line options, but will override the values in the NODE_OPTIONS
env file parsed by the --env-file flag.

If duplicate keys are present in the configuration file, only
the first key will be used.

The configuration parser will throw an error if the configuration file contains
unknown keys or keys that cannot used in NODE_OPTIONS.

Node.js will not sanitize or perform validation on the user-provided configuration,
so NEVER use untrusted configuration files.

--experimental-default-config-file#

Added in: v23.10.0

If the --experimental-default-config-file flag is present, Node.js will look for a
node.config.json file in the current working directory and load it as a
as configuration file.

--experimental-eventsource#

Added in: v22.3.0, v20.18.0

Enable exposition of EventSource Web API on the global scope.

--experimental-import-meta-resolve#

Enable experimental import.meta.resolve() parent URL support, which allows
passing a second parentURL argument for contextual resolution.

Previously gated the entire import.meta.resolve feature.

--experimental-network-inspection#

Added in: v22.6.0, v20.18.0

Enable experimental support for the network inspection with Chrome DevTools.

--experimental-print-required-tla#

Added in: v22.0.0, v20.17.0

If the ES module being require()‘d contains top-level await, this flag
allows Node.js to evaluate the module, try to locate the
top-level awaits, and print their location to help users find them.

--experimental-shadow-realm#

Added in: v19.0.0, v18.13.0

Use this flag to enable ShadowRealm support.

--experimental-test-coverage#

When used in conjunction with the node:test module, a code coverage report is
generated as part of the test runner output. If no tests are run, a coverage
report is not generated. See the documentation on
collecting code coverage from tests for more details.

--experimental-test-module-mocks#

Enable module mocking in the test runner.

This feature requires --allow-worker if used with the Permission Model.

--experimental-transform-types#

Added in: v22.7.0

Enables the transformation of TypeScript-only syntax into JavaScript code.
Implies --enable-source-maps.

--experimental-vm-modules#

Added in: v9.6.0

Enable experimental ES Module support in the node:vm module.

--experimental-wasi-unstable-preview1#

Enable experimental WebAssembly System Interface (WASI) support.

--experimental-wasm-modules#

Added in: v12.3.0

Enable experimental WebAssembly module support.

--experimental-webstorage#

Added in: v22.4.0

Enable experimental Web Storage support.

--expose-gc#

Added in: v22.3.0, v20.18.0

Stability: 1 — Experimental. This flag is inherited from V8 and is subject to
change upstream.

This flag will expose the gc extension from V8.

if (globalThis.gc) {
  globalThis.gc();
} 

--force-context-aware#

Added in: v12.12.0

Disable loading native addons that are not context-aware.

--force-fips#

Added in: v6.0.0

Force FIPS-compliant crypto on startup. (Cannot be disabled from script code.)
(Same requirements as --enable-fips.)

--force-node-api-uncaught-exceptions-policy#

Added in: v18.3.0, v16.17.0

Enforces uncaughtException event on Node-API asynchronous callbacks.

To prevent from an existing add-on from crashing the process, this flag is not
enabled by default. In the future, this flag will be enabled by default to
enforce the correct behavior.

--frozen-intrinsics#

Added in: v11.12.0

Enable experimental frozen intrinsics like Array and Object.

Only the root context is supported. There is no guarantee that
globalThis.Array is indeed the default intrinsic reference. Code may break
under this flag.

To allow polyfills to be added,
--require and --import both run before freezing intrinsics.

--heap-prof#

Starts the V8 heap profiler on start up, and writes the heap profile to disk
before exit.

If --heap-prof-dir is not specified, the generated profile is placed
in the current working directory.

If --heap-prof-name is not specified, the generated profile is
named Heap.${yyyymmdd}.${hhmmss}.${pid}.${tid}.${seq}.heapprofile.

$ node --heap-prof index.js
$ ls *.heapprofile
Heap.20190409.202950.15293.0.001.heapprofile 

--heap-prof-dir#

Specify the directory where the heap profiles generated by --heap-prof will
be placed.

The default value is controlled by the
--diagnostic-dir command-line option.

--heap-prof-interval#

Specify the average sampling interval in bytes for the heap profiles generated
by --heap-prof. The default is 512 * 1024 bytes.

--heap-prof-name#

Specify the file name of the heap profile generated by --heap-prof.

--heapsnapshot-near-heap-limit=max_count#

Added in: v15.1.0, v14.18.0

Writes a V8 heap snapshot to disk when the V8 heap usage is approaching the
heap limit. count should be a non-negative integer (in which case
Node.js will write no more than max_count snapshots to disk).

When generating snapshots, garbage collection may be triggered and bring
the heap usage down. Therefore multiple snapshots may be written to disk
before the Node.js instance finally runs out of memory. These heap snapshots
can be compared to determine what objects are being allocated during the
time consecutive snapshots are taken. It’s not guaranteed that Node.js will
write exactly max_count snapshots to disk, but it will try
its best to generate at least one and up to max_count snapshots before the
Node.js instance runs out of memory when max_count is greater than 0.

Generating V8 snapshots takes time and memory (both memory managed by the
V8 heap and native memory outside the V8 heap). The bigger the heap is,
the more resources it needs. Node.js will adjust the V8 heap to accommodate
the additional V8 heap memory overhead, and try its best to avoid using up
all the memory available to the process. When the process uses
more memory than the system deems appropriate, the process may be terminated
abruptly by the system, depending on the system configuration.

$ node --max-old-space-size=100 --heapsnapshot-near-heap-limit=3 index.js
Wrote snapshot to Heap.20200430.100036.49580.0.001.heapsnapshot
Wrote snapshot to Heap.20200430.100037.49580.0.002.heapsnapshot
Wrote snapshot to Heap.20200430.100038.49580.0.003.heapsnapshot

<--- Last few GCs --->

[49580:0x110000000]     4826 ms: Mark-sweep 130.6 (147.8) -> 130.5 (147.8) MB, 27.4 / 0.0 ms  (average mu = 0.126, current mu = 0.034) allocation failure scavenge might not succeed
[49580:0x110000000]     4845 ms: Mark-sweep 130.6 (147.8) -> 130.6 (147.8) MB, 18.8 / 0.0 ms  (average mu = 0.088, current mu = 0.031) allocation failure scavenge might not succeed


<--- JS stacktrace --->

FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory
.... 

--heapsnapshot-signal=signal#

Added in: v12.0.0

Enables a signal handler that causes the Node.js process to write a heap dump
when the specified signal is received. signal must be a valid signal name.
Disabled by default.

$ node --heapsnapshot-signal=SIGUSR2 index.js &
$ ps aux
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
node         1  5.5  6.1 787252 247004 ?       Ssl  16:43   0:02 node --heapsnapshot-signal=SIGUSR2 index.js
$ kill -USR2 1
$ ls
Heap.20190718.133405.15554.0.001.heapsnapshot 

-h, --help#

Added in: v0.1.3

Print node command-line options.
The output of this option is less detailed than this document.

--icu-data-dir=file#

Added in: v0.11.15

Specify ICU data load path. (Overrides NODE_ICU_DATA.)

--import=module#

Added in: v19.0.0, v18.18.0

Preload the specified module at startup. If the flag is provided several times,
each module will be executed sequentially in the order they appear, starting
with the ones provided in NODE_OPTIONS.

Follows ECMAScript module resolution rules.
Use --require to load a CommonJS module.
Modules preloaded with --require will run before modules preloaded with --import.

Modules are preloaded into the main thread as well as any worker threads,
forked processes, or clustered processes.

--input-type=type#

Added in: v12.0.0

This configures Node.js to interpret --eval or STDIN input as CommonJS or
as an ES module. Valid values are "commonjs", "module", "module-typescript" and "commonjs-typescript".
The "-typescript" values are not available with the flag --no-experimental-strip-types.
The default is "commonjs".

If --input-type is not provided,
Node.js will try to detect the syntax with the following steps:

  1. Run the input as CommonJS.
  2. If step 1 fails, run the input as an ES module.
  3. If step 2 fails with a SyntaxError, strip the types.
  4. If step 3 fails with an error code ERR_UNSUPPORTED_TYPESCRIPT_SYNTAX
    or ERR_INVALID_TYPESCRIPT_SYNTAX,
    throw the error from step 2, including the TypeScript error in the message,
    else run as CommonJS.
  5. If step 4 fails, run the input as an ES module.

To avoid the delay of multiple syntax detection passes, the --input-type=type flag can be used to specify
how the --eval input should be interpreted.

The REPL does not support this option. Usage of --input-type=module with
--print will throw an error, as --print does not support ES module
syntax.

--insecure-http-parser#

Added in: v13.4.0, v12.15.0, v10.19.0

Enable leniency flags on the HTTP parser. This may allow
interoperability with non-conformant HTTP implementations.

When enabled, the parser will accept the following:

  • Invalid HTTP headers values.
  • Invalid HTTP versions.
  • Allow message containing both Transfer-Encoding
    and Content-Length headers.
  • Allow extra data after message when Connection: close is present.
  • Allow extra transfer encodings after chunked has been provided.
  • Allow \n to be used as token separator instead of \r\n.
  • Allow \r\n not to be provided after a chunk.
  • Allow spaces to be present after a chunk size and before \r\n.

All the above will expose your application to request smuggling
or poisoning attack. Avoid using this option.

Warning: binding inspector to a public IP:port combination is insecure#

Binding the inspector to a public IP (including 0.0.0.0) with an open port is
insecure, as it allows external hosts to connect to the inspector and perform
a remote code execution attack.

If specifying a host, make sure that either:

  • The host is not accessible from public networks.
  • A firewall disallows unwanted connections on the port.

More specifically, --inspect=0.0.0.0 is insecure if the port (9229 by
default) is not firewall-protected.

See the debugging security implications section for more information.

--inspect-brk[=[host:]port]#

Added in: v7.6.0

Activate inspector on host:port and break at start of user script.
Default host:port is 127.0.0.1:9229. If port 0 is specified,
a random available port will be used.

See V8 Inspector integration for Node.js for further explanation on Node.js debugger.

--inspect-port=[host:]port#

Added in: v7.6.0

Set the host:port to be used when the inspector is activated.
Useful when activating the inspector by sending the SIGUSR1 signal.
Except when --disable-sigusr1 is passed.

Default host is 127.0.0.1. If port 0 is specified,
a random available port will be used.

See the security warning below regarding the host
parameter usage.

--inspect-publish-uid=stderr,http#

Specify ways of the inspector web socket url exposure.

By default inspector websocket url is available in stderr and under /json/list
endpoint on http://host:port/json/list.

--inspect-wait[=[host:]port]#

Added in: v22.2.0, v20.15.0

Activate inspector on host:port and wait for debugger to be attached.
Default host:port is 127.0.0.1:9229. If port 0 is specified,
a random available port will be used.

See V8 Inspector integration for Node.js for further explanation on Node.js debugger.

--inspect[=[host:]port]#

Added in: v6.3.0

Activate inspector on host:port. Default is 127.0.0.1:9229. If port 0 is
specified, a random available port will be used.

V8 inspector integration allows tools such as Chrome DevTools and IDEs to debug
and profile Node.js instances. The tools attach to Node.js instances via a
tcp port and communicate using the Chrome DevTools Protocol.
See V8 Inspector integration for Node.js for further explanation on Node.js debugger.

-i, --interactive#

Added in: v0.7.7

Opens the REPL even if stdin does not appear to be a terminal.

--jitless#

Added in: v12.0.0

Stability: 1 — Experimental. This flag is inherited from V8 and is subject to
change upstream.

Disable runtime allocation of executable memory. This may be
required on some platforms for security reasons. It can also reduce attack
surface on other platforms, but the performance impact may be severe.

--localstorage-file=file#

Added in: v22.4.0

The file used to store localStorage data. If the file does not exist, it is
created the first time localStorage is accessed. The same file may be shared
between multiple Node.js processes concurrently. This flag is a no-op unless
Node.js is started with the --experimental-webstorage flag.

--max-http-header-size=size#

Specify the maximum size, in bytes, of HTTP headers. Defaults to 16 KiB.

--napi-modules#

Added in: v7.10.0

This option is a no-op. It is kept for compatibility.

--no-addons#

Added in: v16.10.0, v14.19.0

Disable the node-addons exports condition as well as disable loading
native addons. When --no-addons is specified, calling process.dlopen or
requiring a native C++ addon will fail and throw an exception.

--no-deprecation#

Added in: v0.8.0

Silence deprecation warnings.

--no-experimental-detect-module#

Disable using syntax detection to determine module type.

--no-experimental-global-navigator#

Added in: v21.2.0

Disable exposition of Navigator API on the global scope.

--no-experimental-repl-await#

Added in: v16.6.0

Use this flag to disable top-level await in REPL.

--no-experimental-sqlite#

Disable the experimental node:sqlite module.

--no-experimental-strip-types#

Disable experimental type-stripping for TypeScript files.
For more information, see the TypeScript type-stripping documentation.

--no-experimental-websocket#

Added in: v22.0.0

Disable exposition of WebSocket on the global scope.

--no-extra-info-on-fatal-exception#

Added in: v17.0.0

Hide extra information on fatal exception that causes exit.

--no-force-async-hooks-checks#

Added in: v9.0.0

Disables runtime checks for async_hooks. These will still be enabled
dynamically when async_hooks is enabled.

--no-global-search-paths#

Added in: v16.10.0

Do not search modules from global paths like $HOME/.node_modules and
$NODE_PATH.

--no-network-family-autoselection#

Disables the family autoselection algorithm unless connection options explicitly
enables it.

--no-warnings#

Added in: v6.0.0

Silence all process warnings (including deprecations).

--node-memory-debug#

Added in: v15.0.0, v14.18.0

Enable extra debug checks for memory leaks in Node.js internals. This is
usually only useful for developers debugging Node.js itself.

--openssl-config=file#

Added in: v6.9.0

Load an OpenSSL configuration file on startup. Among other uses, this can be
used to enable FIPS-compliant crypto if Node.js is built
against FIPS-enabled OpenSSL.

--openssl-legacy-provider#

Added in: v17.0.0, v16.17.0

Enable OpenSSL 3.0 legacy provider. For more information please see
OSSL_PROVIDER-legacy.

--openssl-shared-config#

Added in: v18.5.0, v16.17.0, v14.21.0

Enable OpenSSL default configuration section, openssl_conf to be read from
the OpenSSL configuration file. The default configuration file is named
openssl.cnf but this can be changed using the environment variable
OPENSSL_CONF, or by using the command line option --openssl-config.
The location of the default OpenSSL configuration file depends on how OpenSSL
is being linked to Node.js. Sharing the OpenSSL configuration may have unwanted
implications and it is recommended to use a configuration section specific to
Node.js which is nodejs_conf and is default when this option is not used.

--pending-deprecation#

Added in: v8.0.0

Emit pending deprecation warnings.

Pending deprecations are generally identical to a runtime deprecation with the
notable exception that they are turned off by default and will not be emitted
unless either the --pending-deprecation command-line flag, or the
NODE_PENDING_DEPRECATION=1 environment variable, is set. Pending deprecations
are used to provide a kind of selective «early warning» mechanism that
developers may leverage to detect deprecated API usage.

--permission#

Enable the Permission Model for current process. When enabled, the
following permissions are restricted:

  • File System — manageable through
    --allow-fs-read, --allow-fs-write flags
  • Child Process — manageable through --allow-child-process flag
  • Worker Threads — manageable through --allow-worker flag
  • WASI — manageable through --allow-wasi flag
  • Addons — manageable through --allow-addons flag

--preserve-symlinks#

Added in: v6.3.0

Instructs the module loader to preserve symbolic links when resolving and
caching modules.

By default, when Node.js loads a module from a path that is symbolically linked
to a different on-disk location, Node.js will dereference the link and use the
actual on-disk «real path» of the module as both an identifier and as a root
path to locate other dependency modules. In most cases, this default behavior
is acceptable. However, when using symbolically linked peer dependencies, as
illustrated in the example below, the default behavior causes an exception to
be thrown if moduleA attempts to require moduleB as a peer dependency:

{appDir}
 ├── app
 │   ├── index.js
 │   └── node_modules
 │       ├── moduleA -> {appDir}/moduleA
 │       └── moduleB
 │           ├── index.js
 │           └── package.json
 └── moduleA
     ├── index.js
     └── package.json 

The --preserve-symlinks command-line flag instructs Node.js to use the
symlink path for modules as opposed to the real path, allowing symbolically
linked peer dependencies to be found.

Note, however, that using --preserve-symlinks can have other side effects.
Specifically, symbolically linked native modules can fail to load if those
are linked from more than one location in the dependency tree (Node.js would
see those as two separate modules and would attempt to load the module multiple
times, causing an exception to be thrown).

The --preserve-symlinks flag does not apply to the main module, which allows
node --preserve-symlinks node_module/.bin/<foo> to work. To apply the same
behavior for the main module, also use --preserve-symlinks-main.

--preserve-symlinks-main#

Added in: v10.2.0

Instructs the module loader to preserve symbolic links when resolving and
caching the main module (require.main).

This flag exists so that the main module can be opted-in to the same behavior
that --preserve-symlinks gives to all other imports; they are separate flags,
however, for backward compatibility with older Node.js versions.

--preserve-symlinks-main does not imply --preserve-symlinks; use
--preserve-symlinks-main in addition to
--preserve-symlinks when it is not desirable to follow symlinks before
resolving relative paths.

See --preserve-symlinks for more information.

-p, --print "script"#

Identical to -e but prints the result.

--prof#

Added in: v2.0.0

Generate V8 profiler output.

--prof-process#

Added in: v5.2.0

Process V8 profiler output generated using the V8 option --prof.

--redirect-warnings=file#

Added in: v8.0.0

Write process warnings to the given file instead of printing to stderr. The
file will be created if it does not exist, and will be appended to if it does.
If an error occurs while attempting to write the warning to the file, the
warning will be written to stderr instead.

The file name may be an absolute path. If it is not, the default directory it
will be written to is controlled by the
--diagnostic-dir command-line option.

--report-compact#

Added in: v13.12.0, v12.17.0

Write reports in a compact format, single-line JSON, more easily consumable
by log processing systems than the default multi-line format designed for
human consumption.

--report-dir=directory, report-directory=directory#

Location at which the report will be generated.

--report-exclude-env#

Added in: v23.3.0

When --report-exclude-env is passed the diagnostic report generated will not
contain the environmentVariables data.

--report-exclude-network#

Added in: v22.0.0, v20.13.0

Exclude header.networkInterfaces from the diagnostic report. By default
this is not set and the network interfaces are included.

--report-filename=filename#

Name of the file to which the report will be written.

If the filename is set to 'stdout' or 'stderr', the report is written to
the stdout or stderr of the process respectively.

--report-on-fatalerror#

Enables the report to be triggered on fatal errors (internal errors within
the Node.js runtime such as out of memory) that lead to termination of the
application. Useful to inspect various diagnostic data elements such as heap,
stack, event loop state, resource consumption etc. to reason about the fatal
error.

--report-on-signal#

Enables report to be generated upon receiving the specified (or predefined)
signal to the running Node.js process. The signal to trigger the report is
specified through --report-signal.

--report-signal=signal#

Sets or resets the signal for report generation (not supported on Windows).
Default signal is SIGUSR2.

--report-uncaught-exception#

Enables report to be generated when the process exits due to an uncaught
exception. Useful when inspecting the JavaScript stack in conjunction with
native stack and other runtime environment data.

-r, --require module#

Preload the specified module at startup.

Follows require()‘s module resolution
rules. module may be either a path to a file, or a node module name.

Modules preloaded with --require will run before modules preloaded with --import.

Modules are preloaded into the main thread as well as any worker threads,
forked processes, or clustered processes.

--run#

This runs a specified command from a package.json’s "scripts" object.
If a missing "command" is provided, it will list the available scripts.

--run will traverse up to the root directory and finds a package.json
file to run the command from.

--run prepends ./node_modules/.bin for each ancestor of
the current directory, to the PATH in order to execute the binaries from
different folders where multiple node_modules directories are present, if
ancestor-folder/node_modules/.bin is a directory.

--run executes the command in the directory containing the related package.json.

For example, the following command will run the test script of
the package.json in the current folder:

$ node --run test 

You can also pass arguments to the command. Any argument after -- will
be appended to the script:

$ node --run test -- --verbose 
Intentional limitations#

node --run is not meant to match the behaviors of npm run or of the run
commands of other package managers. The Node.js implementation is intentionally
more limited, in order to focus on top performance for the most common use
cases.
Some features of other run implementations that are intentionally excluded
are:

  • Running pre or post scripts in addition to the specified script.
  • Defining package manager-specific environment variables.
Environment variables#

The following environment variables are set when running a script with --run:

  • NODE_RUN_SCRIPT_NAME: The name of the script being run. For example, if
    --run is used to run test, the value of this variable will be test.
  • NODE_RUN_PACKAGE_JSON_PATH: The path to the package.json that is being
    processed.

--secure-heap-min=n#

Added in: v15.6.0

When using --secure-heap, the --secure-heap-min flag specifies the
minimum allocation from the secure heap. The minimum value is 2.
The maximum value is the lesser of --secure-heap or 2147483647.
The value given must be a power of two.

--secure-heap=n#

Added in: v15.6.0

Initializes an OpenSSL secure heap of n bytes. When initialized, the
secure heap is used for selected types of allocations within OpenSSL
during key generation and other operations. This is useful, for instance,
to prevent sensitive information from leaking due to pointer overruns
or underruns.

The secure heap is a fixed size and cannot be resized at runtime so,
if used, it is important to select a large enough heap to cover all
application uses.

The heap size given must be a power of two. Any value less than 2
will disable the secure heap.

The secure heap is disabled by default.

The secure heap is not available on Windows.

See CRYPTO_secure_malloc_init for more details.

--snapshot-blob=path#

Added in: v18.8.0

When used with --build-snapshot, --snapshot-blob specifies the path
where the generated snapshot blob is written to. If not specified, the
generated blob is written to snapshot.blob in the current working directory.

When used without --build-snapshot, --snapshot-blob specifies the
path to the blob that is used to restore the application state.

When loading a snapshot, Node.js checks that:

  1. The version, architecture, and platform of the running Node.js binary
    are exactly the same as that of the binary that generates the snapshot.
  2. The V8 flags and CPU features are compatible with that of the binary
    that generates the snapshot.

If they don’t match, Node.js refuses to load the snapshot and exits with
status code 1.

--test#

Starts the Node.js command line test runner. This flag cannot be combined with
--watch-path, --check, --eval, --interactive, or the inspector.
See the documentation on running tests from the command line
for more details.

--test-concurrency#

Added in: v21.0.0, v20.10.0, v18.19.0

The maximum number of test files that the test runner CLI will execute
concurrently. If --test-isolation is set to 'none', this flag is ignored and
concurrency is one. Otherwise, concurrency defaults to
os.availableParallelism() - 1.

--test-coverage-branches=threshold#

Added in: v22.8.0

Require a minimum percent of covered branches. If code coverage does not reach
the threshold specified, the process will exit with code 1.

--test-coverage-exclude#

Added in: v22.5.0

Excludes specific files from code coverage using a glob pattern, which can match
both absolute and relative file paths.

This option may be specified multiple times to exclude multiple glob patterns.

If both --test-coverage-exclude and --test-coverage-include are provided,
files must meet both criteria to be included in the coverage report.

By default all the matching test files are excluded from the coverage report.
Specifying this option will override the default behavior.

--test-coverage-functions=threshold#

Added in: v22.8.0

Require a minimum percent of covered functions. If code coverage does not reach
the threshold specified, the process will exit with code 1.

--test-coverage-include#

Added in: v22.5.0

Includes specific files in code coverage using a glob pattern, which can match
both absolute and relative file paths.

This option may be specified multiple times to include multiple glob patterns.

If both --test-coverage-exclude and --test-coverage-include are provided,
files must meet both criteria to be included in the coverage report.

--test-coverage-lines=threshold#

Added in: v22.8.0

Require a minimum percent of covered lines. If code coverage does not reach
the threshold specified, the process will exit with code 1.

--test-force-exit#

Added in: v22.0.0, v20.14.0

Configures the test runner to exit the process once all known tests have
finished executing even if the event loop would otherwise remain active.

--test-isolation=mode#

Configures the type of test isolation used in the test runner. When mode is
'process', each test file is run in a separate child process. When mode is
'none', all test files run in the same process as the test runner. The default
isolation mode is 'process'. This flag is ignored if the --test flag is not
present. See the test runner execution model section for more information.

--test-name-pattern#

A regular expression that configures the test runner to only execute tests
whose name matches the provided pattern. See the documentation on
filtering tests by name for more details.

If both --test-name-pattern and --test-skip-pattern are supplied,
tests must satisfy both requirements in order to be executed.

--test-only#

Configures the test runner to only execute top level tests that have the only
option set. This flag is not necessary when test isolation is disabled.

--test-reporter#

A test reporter to use when running tests. See the documentation on
test reporters for more details.

--test-reporter-destination#

The destination for the corresponding test reporter. See the documentation on
test reporters for more details.

--test-shard#

Added in: v20.5.0, v18.19.0

Test suite shard to execute in a format of <index>/<total>, where

index is a positive integer, index of divided parts
total is a positive integer, total of divided part
This command will divide all tests files into total equal parts,
and will run only those that happen to be in an index part.

For example, to split your tests suite into three parts, use this:

node --test --test-shard=1/3
node --test --test-shard=2/3
node --test --test-shard=3/3 

--test-skip-pattern#

Added in: v22.1.0

A regular expression that configures the test runner to skip tests
whose name matches the provided pattern. See the documentation on
filtering tests by name for more details.

If both --test-name-pattern and --test-skip-pattern are supplied,
tests must satisfy both requirements in order to be executed.

--test-timeout#

Added in: v21.2.0, v20.11.0

A number of milliseconds the test execution will fail after. If unspecified,
subtests inherit this value from their parent. The default value is Infinity.

--test-update-snapshots#

Regenerates the snapshot files used by the test runner for snapshot testing.

--throw-deprecation#

Added in: v0.11.14

Throw errors for deprecations.

--title=title#

Added in: v10.7.0

Set process.title on startup.

--tls-cipher-list=list#

Added in: v4.0.0

Specify an alternative default TLS cipher list. Requires Node.js to be built
with crypto support (default).

--tls-keylog=file#

Added in: v13.2.0, v12.16.0

Log TLS key material to a file. The key material is in NSS SSLKEYLOGFILE
format and can be used by software (such as Wireshark) to decrypt the TLS
traffic.

--tls-max-v1.2#

Added in: v12.0.0, v10.20.0

Set tls.DEFAULT_MAX_VERSION to ‘TLSv1.2’. Use to disable support for
TLSv1.3.

--tls-max-v1.3#

Added in: v12.0.0

Set default tls.DEFAULT_MAX_VERSION to ‘TLSv1.3’. Use to enable support
for TLSv1.3.

--tls-min-v1.0#

Added in: v12.0.0, v10.20.0

Set default tls.DEFAULT_MIN_VERSION to ‘TLSv1’. Use for compatibility with
old TLS clients or servers.

--tls-min-v1.1#

Added in: v12.0.0, v10.20.0

Set default tls.DEFAULT_MIN_VERSION to ‘TLSv1.1’. Use for compatibility
with old TLS clients or servers.

--tls-min-v1.2#

Added in: v12.2.0, v10.20.0

Set default tls.DEFAULT_MIN_VERSION to ‘TLSv1.2’. This is the default for
12.x and later, but the option is supported for compatibility with older Node.js
versions.

--tls-min-v1.3#

Added in: v12.0.0

Set default tls.DEFAULT_MIN_VERSION to ‘TLSv1.3’. Use to disable support
for TLSv1.2, which is not as secure as TLSv1.3.

--trace-deprecation#

Added in: v0.8.0

Print stack traces for deprecations.

--trace-env#

Added in: v23.4.0

Print information about any access to environment variables done in the current Node.js
instance to stderr, including:

  • The environment variable reads that Node.js does internally.
  • Writes in the form of process.env.KEY = "SOME VALUE".
  • Reads in the form of process.env.KEY.
  • Definitions in the form of Object.defineProperty(process.env, 'KEY', {...}).
  • Queries in the form of Object.hasOwn(process.env, 'KEY'),
    process.env.hasOwnProperty('KEY') or 'KEY' in process.env.
  • Deletions in the form of delete process.env.KEY.
  • Enumerations inf the form of ...process.env or Object.keys(process.env).

Only the names of the environment variables being accessed are printed. The values are not printed.

To print the stack trace of the access, use --trace-env-js-stack and/or
--trace-env-native-stack.

--trace-env-js-stack#

Added in: v23.4.0

In addition to what --trace-env does, this prints the JavaScript stack trace of the access.

--trace-env-native-stack#

Added in: v23.4.0

In addition to what --trace-env does, this prints the native stack trace of the access.

--trace-event-categories#

Added in: v7.7.0

A comma separated list of categories that should be traced when trace event
tracing is enabled using --trace-events-enabled.

--trace-event-file-pattern#

Added in: v9.8.0

Template string specifying the filepath for the trace event data, it
supports ${rotation} and ${pid}.

--trace-events-enabled#

Added in: v7.7.0

Enables the collection of trace event tracing information.

--trace-exit#

Added in: v13.5.0, v12.16.0

Prints a stack trace whenever an environment is exited proactively,
i.e. invoking process.exit().

--trace-require-module=mode#

Added in: v23.5.0

Prints information about usage of Loading ECMAScript modules using require().

When mode is all, all usage is printed. When mode is no-node-modules, usage
from the node_modules folder is excluded.

--trace-sigint#

Added in: v13.9.0, v12.17.0

Prints a stack trace on SIGINT.

--trace-sync-io#

Added in: v2.1.0

Prints a stack trace whenever synchronous I/O is detected after the first turn
of the event loop.

--trace-tls#

Added in: v12.2.0

Prints TLS packet trace information to stderr. This can be used to debug TLS
connection problems.

--trace-uncaught#

Added in: v13.1.0

Print stack traces for uncaught exceptions; usually, the stack trace associated
with the creation of an Error is printed, whereas this makes Node.js also
print the stack trace associated with throwing the value (which does not need
to be an Error instance).

Enabling this option may affect garbage collection behavior negatively.

--trace-warnings#

Added in: v6.0.0

Print stack traces for process warnings (including deprecations).

--track-heap-objects#

Added in: v2.4.0

Track heap object allocations for heap snapshots.

--unhandled-rejections=mode#

Using this flag allows to change what should happen when an unhandled rejection
occurs. One of the following modes can be chosen:

  • throw: Emit unhandledRejection. If this hook is not set, raise the
    unhandled rejection as an uncaught exception. This is the default.
  • strict: Raise the unhandled rejection as an uncaught exception. If the
    exception is handled, unhandledRejection is emitted.
  • warn: Always trigger a warning, no matter if the unhandledRejection
    hook is set or not but do not print the deprecation warning.
  • warn-with-error-code: Emit unhandledRejection. If this hook is not
    set, trigger a warning, and set the process exit code to 1.
  • none: Silence all warnings.

If a rejection happens during the command line entry point’s ES module static
loading phase, it will always raise it as an uncaught exception.

--use-bundled-ca, --use-openssl-ca#

Added in: v6.11.0

Use bundled Mozilla CA store as supplied by current Node.js version
or use OpenSSL’s default CA store. The default store is selectable
at build-time.

The bundled CA store, as supplied by Node.js, is a snapshot of Mozilla CA store
that is fixed at release time. It is identical on all supported platforms.

Using OpenSSL store allows for external modifications of the store. For most
Linux and BSD distributions, this store is maintained by the distribution
maintainers and system administrators. OpenSSL CA store location is dependent on
configuration of the OpenSSL library but this can be altered at runtime using
environment variables.

See SSL_CERT_DIR and SSL_CERT_FILE.

--use-largepages=mode#

Added in: v13.6.0, v12.17.0

Re-map the Node.js static code to large memory pages at startup. If supported on
the target system, this will cause the Node.js static code to be moved onto 2
MiB pages instead of 4 KiB pages.

The following values are valid for mode:

  • off: No mapping will be attempted. This is the default.
  • on: If supported by the OS, mapping will be attempted. Failure to map will
    be ignored and a message will be printed to standard error.
  • silent: If supported by the OS, mapping will be attempted. Failure to map
    will be ignored and will not be reported.

--use-system-ca#

Node.js uses the trusted CA certificates present in the system store along with
the --use-bundled-ca option and the NODE_EXTRA_CA_CERTS environment variable.
On platforms other than Windows and macOS, this loads certificates from the directory
and file trusted by OpenSSL, similar to --use-openssl-ca, with the difference being
that it caches the certificates after first load.

On Windows and macOS, the certificate trust policy is planned to follow
Chromium’s policy for locally trusted certificates:

On macOS, the following settings are respected:

  • Default and System Keychains
    • Trust:
      • Any certificate where the “When using this certificate” flag is set to “Always Trust” or
      • Any certificate where the “Secure Sockets Layer (SSL)” flag is set to “Always Trust.”
    • Distrust:
      • Any certificate where the “When using this certificate” flag is set to “Never Trust” or
      • Any certificate where the “Secure Sockets Layer (SSL)” flag is set to “Never Trust.”

On Windows, the following settings are respected (unlike Chromium’s policy, distrust
and intermediate CA are not currently supported):

  • Local Machine (accessed via certlm.msc)
    • Trust:
      • Trusted Root Certification Authorities
      • Trusted People
      • Enterprise Trust -> Enterprise -> Trusted Root Certification Authorities
      • Enterprise Trust -> Enterprise -> Trusted People
      • Enterprise Trust -> Group Policy -> Trusted Root Certification Authorities
      • Enterprise Trust -> Group Policy -> Trusted People
  • Current User (accessed via certmgr.msc)
    • Trust:
      • Trusted Root Certification Authorities
      • Enterprise Trust -> Group Policy -> Trusted Root Certification Authorities

On Windows and macOS, Node.js would check that the user settings for the certificates
do not forbid them for TLS server authentication before using them.

On other systems, Node.js loads certificates from the default certificate file
(typically /etc/ssl/cert.pem) and default certificate directory (typically
/etc/ssl/certs) that the version of OpenSSL that Node.js links to respects.
This typically works with the convention on major Linux distributions and other
Unix-like systems. If the overriding OpenSSL environment variables
(typically SSL_CERT_FILE and SSL_CERT_DIR, depending on the configuration
of the OpenSSL that Node.js links to) are set, the specified paths will be used to load
certificates instead. These environment variables can be used as workarounds
if the conventional paths used by the version of OpenSSL Node.js links to are
not consistent with the system configuration that the users have for some reason.

--v8-options#

Added in: v0.1.3

Print V8 command-line options.

--v8-pool-size=num#

Added in: v5.10.0

Set V8’s thread pool size which will be used to allocate background jobs.

If set to 0 then Node.js will choose an appropriate size of the thread pool
based on an estimate of the amount of parallelism.

The amount of parallelism refers to the number of computations that can be
carried out simultaneously in a given machine. In general, it’s the same as the
amount of CPUs, but it may diverge in environments such as VMs or containers.

-v, --version#

Added in: v0.1.3

Print node’s version.

--watch#

Starts Node.js in watch mode.
When in watch mode, changes in the watched files cause the Node.js process to
restart.
By default, watch mode will watch the entry point
and any required or imported module.
Use --watch-path to specify what paths to watch.

This flag cannot be combined with
--check, --eval, --interactive, or the REPL.

node --watch index.js 

--watch-path#

Starts Node.js in watch mode and specifies what paths to watch.
When in watch mode, changes in the watched paths cause the Node.js process to
restart.
This will turn off watching of required or imported modules, even when used in
combination with --watch.

This flag cannot be combined with
--check, --eval, --interactive, --test, or the REPL.

node --watch-path=./src --watch-path=./tests index.js 

This option is only supported on macOS and Windows.
An ERR_FEATURE_UNAVAILABLE_ON_PLATFORM exception will be thrown
when the option is used on a platform that does not support it.

--watch-preserve-output#

Added in: v19.3.0, v18.13.0

Disable the clearing of the console when watch mode restarts the process.

node --watch --watch-preserve-output test.js 

--zero-fill-buffers#

Added in: v6.0.0

Automatically zero-fills all newly allocated Buffer and SlowBuffer
instances.

Environment variables#

FORCE_COLOR=[1, 2, 3]#

The FORCE_COLOR environment variable is used to
enable ANSI colorized output. The value may be:

  • 1, true, or the empty string '' indicate 16-color support,
  • 2 to indicate 256-color support, or
  • 3 to indicate 16 million-color support.

When FORCE_COLOR is used and set to a supported value, both the NO_COLOR,
and NODE_DISABLE_COLORS environment variables are ignored.

Any other value will result in colorized output being disabled.

NODE_DEBUG=module[,…]#

Added in: v0.1.32

','-separated list of core modules that should print debug information.

NODE_DEBUG_NATIVE=module[,…]#

','-separated list of core C++ modules that should print debug information.

NODE_DISABLE_COLORS=1#

Added in: v0.3.0

When set, colors will not be used in the REPL.

NODE_EXTRA_CA_CERTS=file#

Added in: v7.3.0

When set, the well known «root» CAs (like VeriSign) will be extended with the
extra certificates in file. The file should consist of one or more trusted
certificates in PEM format. A message will be emitted (once) with
process.emitWarning() if the file is missing or
malformed, but any errors are otherwise ignored.

Neither the well known nor extra certificates are used when the ca
options property is explicitly specified for a TLS or HTTPS client or server.

This environment variable is ignored when node runs as setuid root or
has Linux file capabilities set.

The NODE_EXTRA_CA_CERTS environment variable is only read when the Node.js
process is first launched. Changing the value at runtime using
process.env.NODE_EXTRA_CA_CERTS has no effect on the current process.

NODE_ICU_DATA=file#

Added in: v0.11.15

Data path for ICU (Intl object) data. Will extend linked-in data when compiled
with small-icu support.

NODE_NO_WARNINGS=1#

Added in: v6.11.0

When set to 1, process warnings are silenced.

NODE_OPTIONS=options...#

Added in: v8.0.0

A space-separated list of command-line options. options... are interpreted
before command-line options, so command-line options will override or
compound after anything in options.... Node.js will exit with an error if
an option that is not allowed in the environment is used, such as -p or a
script file.

If an option value contains a space, it can be escaped using double quotes:

NODE_OPTIONS='--require "./my path/file.js"' 

A singleton flag passed as a command-line option will override the same flag
passed into NODE_OPTIONS:

# The inspector will be available on port 5555
NODE_OPTIONS='--inspect=localhost:4444' node --inspect=localhost:5555 

A flag that can be passed multiple times will be treated as if its
NODE_OPTIONS instances were passed first, and then its command-line
instances afterwards:

NODE_OPTIONS='--require "./a.js"' node --require "./b.js"
# is equivalent to:
node --require "./a.js" --require "./b.js" 

Node.js options that are allowed are in the following list. If an option
supports both —XX and —no-XX variants, they are both supported but only
one is included in the list below.

  • --allow-addons
  • --allow-child-process
  • --allow-fs-read
  • --allow-fs-write
  • --allow-wasi
  • --allow-worker
  • --conditions, -C
  • --cpu-prof-dir
  • --cpu-prof-interval
  • --cpu-prof-name
  • --cpu-prof
  • --diagnostic-dir
  • --disable-proto
  • --disable-sigusr1
  • --disable-warning
  • --disable-wasm-trap-handler
  • --dns-result-order
  • --enable-fips
  • --enable-network-family-autoselection
  • --enable-source-maps
  • --entry-url
  • --experimental-abortcontroller
  • --experimental-addon-modules
  • --experimental-async-context-frame
  • --experimental-detect-module
  • --experimental-eventsource
  • --experimental-import-meta-resolve
  • --experimental-json-modules
  • --experimental-loader
  • --experimental-modules
  • --experimental-permission
  • --experimental-print-required-tla
  • --experimental-require-module
  • --experimental-shadow-realm
  • --experimental-specifier-resolution
  • --experimental-test-isolation
  • --experimental-top-level-await
  • --experimental-transform-types
  • --experimental-vm-modules
  • --experimental-wasi-unstable-preview1
  • --experimental-wasm-modules
  • --experimental-webstorage
  • --force-context-aware
  • --force-fips
  • --force-node-api-uncaught-exceptions-policy
  • --frozen-intrinsics
  • --heap-prof-dir
  • --heap-prof-interval
  • --heap-prof-name
  • --heap-prof
  • --heapsnapshot-near-heap-limit
  • --heapsnapshot-signal
  • --http-parser
  • --icu-data-dir
  • --import
  • --input-type
  • --insecure-http-parser
  • --inspect-brk
  • --inspect-port, --debug-port
  • --inspect-publish-uid
  • --inspect-wait
  • --inspect
  • --localstorage-file
  • --max-http-header-size
  • --napi-modules
  • --network-family-autoselection-attempt-timeout
  • --no-addons
  • --no-deprecation
  • --no-experimental-global-navigator
  • --no-experimental-repl-await
  • --no-experimental-sqlite
  • --no-experimental-strip-types
  • --no-experimental-websocket
  • --no-extra-info-on-fatal-exception
  • --no-force-async-hooks-checks
  • --no-global-search-paths
  • --no-network-family-autoselection
  • --no-warnings
  • --node-memory-debug
  • --openssl-config
  • --openssl-legacy-provider
  • --openssl-shared-config
  • --pending-deprecation
  • --permission
  • --preserve-symlinks-main
  • --preserve-symlinks
  • --prof-process
  • --redirect-warnings
  • --report-compact
  • --report-dir, --report-directory
  • --report-exclude-env
  • --report-exclude-network
  • --report-filename
  • --report-on-fatalerror
  • --report-on-signal
  • --report-signal
  • --report-uncaught-exception
  • --require, -r
  • --secure-heap-min
  • --secure-heap
  • --snapshot-blob
  • --test-coverage-branches
  • --test-coverage-exclude
  • --test-coverage-functions
  • --test-coverage-include
  • --test-coverage-lines
  • --test-isolation
  • --test-name-pattern
  • --test-only
  • --test-reporter-destination
  • --test-reporter
  • --test-shard
  • --test-skip-pattern
  • --throw-deprecation
  • --title
  • --tls-cipher-list
  • --tls-keylog
  • --tls-max-v1.2
  • --tls-max-v1.3
  • --tls-min-v1.0
  • --tls-min-v1.1
  • --tls-min-v1.2
  • --tls-min-v1.3
  • --trace-deprecation
  • --trace-env-js-stack
  • --trace-env-native-stack
  • --trace-env
  • --trace-event-categories
  • --trace-event-file-pattern
  • --trace-events-enabled
  • --trace-exit
  • --trace-require-module
  • --trace-sigint
  • --trace-sync-io
  • --trace-tls
  • --trace-uncaught
  • --trace-warnings
  • --track-heap-objects
  • --unhandled-rejections
  • --use-bundled-ca
  • --use-largepages
  • --use-openssl-ca
  • --use-system-ca
  • --v8-pool-size
  • --watch-path
  • --watch-preserve-output
  • --watch
  • --zero-fill-buffers

V8 options that are allowed are:

  • --abort-on-uncaught-exception
  • --disallow-code-generation-from-strings
  • --enable-etw-stack-walking
  • --expose-gc
  • --interpreted-frames-native-stack
  • --jitless
  • --max-old-space-size
  • --max-semi-space-size
  • --perf-basic-prof-only-functions
  • --perf-basic-prof
  • --perf-prof-unwinding-info
  • --perf-prof
  • --stack-trace-limit

--perf-basic-prof-only-functions, --perf-basic-prof,
--perf-prof-unwinding-info, and --perf-prof are only available on Linux.

--enable-etw-stack-walking is only available on Windows.

NODE_PATH=path[:…]#

Added in: v0.1.32

':'-separated list of directories prefixed to the module search path.

On Windows, this is a ';'-separated list instead.

NODE_PENDING_DEPRECATION=1#

Added in: v8.0.0

When set to 1, emit pending deprecation warnings.

Pending deprecations are generally identical to a runtime deprecation with the
notable exception that they are turned off by default and will not be emitted
unless either the --pending-deprecation command-line flag, or the
NODE_PENDING_DEPRECATION=1 environment variable, is set. Pending deprecations
are used to provide a kind of selective «early warning» mechanism that
developers may leverage to detect deprecated API usage.

NODE_PENDING_PIPE_INSTANCES=instances#

Set the number of pending pipe instance handles when the pipe server is waiting
for connections. This setting applies to Windows only.

NODE_PRESERVE_SYMLINKS=1#

Added in: v7.1.0

When set to 1, instructs the module loader to preserve symbolic links when
resolving and caching modules.

NODE_REDIRECT_WARNINGS=file#

Added in: v8.0.0

When set, process warnings will be emitted to the given file instead of
printing to stderr. The file will be created if it does not exist, and will be
appended to if it does. If an error occurs while attempting to write the
warning to the file, the warning will be written to stderr instead. This is
equivalent to using the --redirect-warnings=file command-line flag.

NODE_REPL_EXTERNAL_MODULE=file#

Path to a Node.js module which will be loaded in place of the built-in REPL.
Overriding this value to an empty string ('') will use the built-in REPL.

NODE_REPL_HISTORY=file#

Added in: v3.0.0

Path to the file used to store the persistent REPL history. The default path is
~/.node_repl_history, which is overridden by this variable. Setting the value
to an empty string ('' or ' ') disables persistent REPL history.

NODE_SKIP_PLATFORM_CHECK=value#

Added in: v14.5.0

If value equals '1', the check for a supported platform is skipped during
Node.js startup. Node.js might not execute correctly. Any issues encountered
on unsupported platforms will not be fixed.

NODE_TEST_CONTEXT=value#

If value equals 'child', test reporter options will be overridden and test
output will be sent to stdout in the TAP format. If any other value is provided,
Node.js makes no guarantees about the reporter format used or its stability.

NODE_TLS_REJECT_UNAUTHORIZED=value

If value equals '0', certificate validation is disabled for TLS connections.
This makes TLS, and HTTPS by extension, insecure. The use of this environment
variable is strongly discouraged.

NODE_V8_COVERAGE=dir#

When set, Node.js will begin outputting V8 JavaScript code coverage and
Source Map data to the directory provided as an argument (coverage
information is written as JSON to files with a coverage prefix).

NODE_V8_COVERAGE will automatically propagate to subprocesses, making it
easier to instrument applications that call the child_process.spawn() family
of functions. NODE_V8_COVERAGE can be set to an empty string, to prevent
propagation.

Coverage output#

Coverage is output as an array of ScriptCoverage objects on the top-level
key result:

{
  "result": [
    {
      "scriptId": "67",
      "url": "internal/tty.js",
      "functions": []
    }
  ]
} 
Source map cache#

If found, source map data is appended to the top-level key source-map-cache
on the JSON coverage object.

source-map-cache is an object with keys representing the files source maps
were extracted from, and values which include the raw source-map URL
(in the key url), the parsed Source Map v3 information (in the key data),
and the line lengths of the source file (in the key lineLengths).

{
  "result": [
    {
      "scriptId": "68",
      "url": "file:///absolute/path/to/source.js",
      "functions": []
    }
  ],
  "source-map-cache": {
    "file:///absolute/path/to/source.js": {
      "url": "./path-to-map.json",
      "data": {
        "version": 3,
        "sources": [
          "file:///absolute/path/to/original.js"
        ],
        "names": [
          "Foo",
          "console",
          "info"
        ],
        "mappings": "MAAMA,IACJC,YAAaC",
        "sourceRoot": "./"
      },
      "lineLengths": [
        13,
        62,
        38,
        27
      ]
    }
  }
} 

NO_COLOR=<any>#

NO_COLOR is an alias for NODE_DISABLE_COLORS. The value of the
environment variable is arbitrary.

OPENSSL_CONF=file#

Added in: v6.11.0

Load an OpenSSL configuration file on startup. Among other uses, this can be
used to enable FIPS-compliant crypto if Node.js is built with
./configure --openssl-fips.

If the --openssl-config command-line option is used, the environment
variable is ignored.

SSL_CERT_DIR=dir#

Added in: v7.7.0

If --use-openssl-ca is enabled, or if --use-system-ca is enabled on
platforms other than macOS and Windows, this overrides and sets OpenSSL’s directory
containing trusted certificates.

Be aware that unless the child environment is explicitly set, this environment
variable will be inherited by any child processes, and if they use OpenSSL, it
may cause them to trust the same CAs as node.

SSL_CERT_FILE=file#

Added in: v7.7.0

If --use-openssl-ca is enabled, or if --use-system-ca is enabled on
platforms other than macOS and Windows, this overrides and sets OpenSSL’s file
containing trusted certificates.

Be aware that unless the child environment is explicitly set, this environment
variable will be inherited by any child processes, and if they use OpenSSL, it
may cause them to trust the same CAs as node.

TZ#

The TZ environment variable is used to specify the timezone configuration.

While Node.js does not support all of the various ways that TZ is handled in
other environments, it does support basic timezone IDs (such as
'Etc/UTC', 'Europe/Paris', or 'America/New_York').
It may support a few other abbreviations or aliases, but these are strongly
discouraged and not guaranteed.

$ TZ=Europe/Dublin node -pe "new Date().toString()"
Wed May 12 2021 20:30:48 GMT+0100 (Irish Standard Time) 

UV_THREADPOOL_SIZE=size#

Set the number of threads used in libuv’s threadpool to size threads.

Asynchronous system APIs are used by Node.js whenever possible, but where they
do not exist, libuv’s threadpool is used to create asynchronous node APIs based
on synchronous system APIs. Node.js APIs that use the threadpool are:

  • all fs APIs, other than the file watcher APIs and those that are explicitly
    synchronous
  • asynchronous crypto APIs such as crypto.pbkdf2(), crypto.scrypt(),
    crypto.randomBytes(), crypto.randomFill(), crypto.generateKeyPair()
  • dns.lookup()
  • all zlib APIs, other than those that are explicitly synchronous

Because libuv’s threadpool has a fixed size, it means that if for whatever
reason any of these APIs takes a long time, other (seemingly unrelated) APIs
that run in libuv’s threadpool will experience degraded performance. In order to
mitigate this issue, one potential solution is to increase the size of libuv’s
threadpool by setting the 'UV_THREADPOOL_SIZE' environment variable to a value
greater than 4 (its current default value). However, setting this from inside
the process using process.env.UV_THREADPOOL_SIZE=size is not guranteed to work
as the threadpool would have been created as part of the runtime initialisation
much before user code is run. For more information, see the libuv threadpool documentation.

Useful V8 options#

V8 has its own set of CLI options. Any V8 CLI option that is provided to node
will be passed on to V8 to handle. V8’s options have no stability guarantee.
The V8 team themselves don’t consider them to be part of their formal API,
and reserve the right to change them at any time. Likewise, they are not
covered by the Node.js stability guarantees. Many of the V8
options are of interest only to V8 developers. Despite this, there is a small
set of V8 options that are widely applicable to Node.js, and they are
documented here:

--abort-on-uncaught-exception#

--disallow-code-generation-from-strings#

--enable-etw-stack-walking#

--expose-gc#

--harmony-shadow-realm#

--interpreted-frames-native-stack#

--jitless#

--max-old-space-size=SIZE (in MiB)#

Sets the max memory size of V8’s old memory section. As memory
consumption approaches the limit, V8 will spend more time on
garbage collection in an effort to free unused memory.

On a machine with 2 GiB of memory, consider setting this to
1536 (1.5 GiB) to leave some memory for other uses and avoid swapping.

node --max-old-space-size=1536 index.js 

--max-semi-space-size=SIZE (in MiB)#

Sets the maximum semi-space size for V8’s scavenge garbage collector in
MiB (mebibytes).
Increasing the max size of a semi-space may improve throughput for Node.js at
the cost of more memory consumption.

Since the young generation size of the V8 heap is three times (see
YoungGenerationSizeFromSemiSpaceSize in V8) the size of the semi-space,
an increase of 1 MiB to semi-space applies to each of the three individual
semi-spaces and causes the heap size to increase by 3 MiB. The throughput
improvement depends on your workload (see #42511).

The default value depends on the memory limit. For example, on 64-bit systems
with a memory limit of 512 MiB, the max size of a semi-space defaults to 1 MiB.
For memory limits up to and including 2GiB, the default max size of a
semi-space will be less than 16 MiB on 64-bit systems.

To get the best configuration for your application, you should try different
max-semi-space-size values when running benchmarks for your application.

For example, benchmark on a 64-bit systems:

for MiB in 16 32 64 128; do
    node --max-semi-space-size=$MiB index.js
done 

--perf-basic-prof#

--perf-basic-prof-only-functions#

--perf-prof#

--perf-prof-unwinding-info#

--prof#

--security-revert#

--stack-trace-limit=limit#

The maximum number of stack frames to collect in an error’s stack trace.
Setting it to 0 disables stack trace collection. The default value is 10.

node --stack-trace-limit=12 -p -e "Error.stackTraceLimit" # prints 12 

Node.js is an open-source, cross-platform JavaScript runtime environment that allows developers to run JavaScript code server-side, beyond its traditional use in web browsers. Built on Chrome’s V8 JavaScript engine, Node.js is instrumental in creating scalable, interactive web applications capable of efficiently managing concurrent connections in real time.

This guide will teach you how to check Node version after installing Node.js on your system. We will also cover the installation steps of Node.js on Linux and Windows operating systems. But let’s start with the basics.

What Are the Key Features of Node.js?

Node.js boasts a plethora of features that make it a top choice for web application development. Here’s a breakdown of its key attributes.

Event-Driven and Asynchronous

  • Node.js operates on an event-driven model with asynchronous I/O.
  • It performs tasks concurrently, allowing the system to handle other operations simultaneously.
  • This architecture is essential for building responsive and scalable applications.

JavaScript Language Support

  • Node.js utilizes JavaScript for both frontend and backend development.
  • Language continuity enables smooth transitions between different parts of an application.

NPM (Node Package Manager)

  • Node.js includes NPM, a package manager providing a wide range of libraries and modules.
  • Developers can seamlessly integrate third-party solutions, saving time and effort.

Scalability Focus

  • Node.js is designed to manage a high volume of connections without overloading resources.
  • Its non-blocking I/O and event-driven approach enhance scalability, suitable for varying workloads.

Speed Up Code Execution 

  • Node.js leverages the V8 JavaScript engine for quick code execution.
  • This performance contributes to its suitability for real-time applications.

Cross-Platform Compatibility

  • Node.js is compatible with diverse operating systems.
  • Its versatility makes it applicable across different environments.

Server-Side Web Development

  • Node.js is widely used for building server-side components like web servers and APIs.
  • It’s valuable for creating APIs that power frontend frameworks like React, Angular, and Vue.js.

Streaming Capability

  • Node.js excels in managing data streams, making it ideal for tasks involving real-time multimedia streaming and file handling.

How To Check Node Version on Your System? (Ways To Check Node Version)

There are multiple ways to check the Node version running on your system. The following methods can help you find the Node version you are using on different operating systems:

  • Check the Node.js version using the node version command node —version or the shorthand node -v.
  • Check Node version at runtime using process.version property.
  • Manage and check the Node version using NVM.

How To Check Node.js Version on Linux?

Node.js can be installed and run on multiple operating systems, such as Linux, Windows, and macOS. Over time, several Node.js releases have been made available for installation. The best version for you would depend on your specific application needs.

You can check the Node version installed on your system by running the following command:

$ node --version

It will display the Node version on your command-line window running on your system. 

If you don’t have Node.js installed on your Linux system, don’t worry! In this section, we will guide you on how to check Node version with complete Node.js installation on Linux.

You can install Node.js on the Linux Ubuntu distribution using the following steps.

Step 1: Update Your Repositories

Before starting the Node.js installation on your system, ensure that all your Linux system repositories are up to date. Launch the terminal using ‘Ctrl+Alt+T’ or open it from the application menu. 

Now, update apt repositories using the below command:

$ sudo apt update

Step 2: Install Node.js and NPM

Install Node.js on your Linux system by executing the below command:

$ sudo apt install node

Always install the NPM (Node Package Manager) with Node.js or node server. NPM allows you to install open-source libraries and Node.js packages on your system. 

You can install NPM along with the Node.js using this command:

$ sudo apt install Node.js npm

To check the NPM version, you can use the below command:

$ npm –version

how to check node version [step-by-step guide]

Step 3: Verify Node.js Installation

You can verify the Node.js installation on your system using the following command:

$ node –version

how to check node version [step-by-step guide]

Alternatively, you can also check the node version using the node command:

$ node -v

Both commands will display the installed Node.js version on your terminal screen. Using the above method, you can also check the Node.js version on bluevps for Linux.

Uninstall Node.Js 

To uninstall or remove the Node.js version, use the below-mentioned command:

$ sudo apt remove node.js

How To Check Node Version on Windows?

For Windows users, it’s straightforward to install and check Node.js on the system. Before we proceed, ensure you have administrative privileges to run commands on the command prompt. If Node.js isn’t yet installed on your Windows OS, follow these steps:

Step 1: Download the Node.js MSI Installer

Go to the official Node.js website and select the appropriate Node.js Windows Installer based on your system architecture:

  • For a 64-bit system, choose the x64-bit installer.
  • For a 32-bit system, choose the x32-bit installer.

In this guide, we’ll be downloading the stable version, node-v18.14.0.

how to check node version [step-by-step guide]

Step 2: Launch the Installer

After completing the download, navigate to the folder or directory where you store the Node.js installer. You will double-click on the installer to launch the installation wizard.

Step 3: Start the Setup Wizard

The Node.js setup wizard will launch on your system. Click ‘Next’ to proceed.

how to check node version [step-by-step guide]

Step 4: Accept the License Agreement

Accept the terms of the End User License Agreement and click ‘Next.’

how to check node version [step-by-step guide]

Step 5: Choose Installation Path

Select the desired folder for Node.js installation. If you prefer the default path, simply click ‘Next.’

how to check node version [step-by-step guide]

Step 6: Additional Tools

If you want to install tools necessary to compile native modules, mark the checkbox and click ‘Next.’

how to check node version [step-by-step guide]

Step 7: Begin Installation

Now, your setup is ready for installation. Click ‘Install’ to start the Node.js installation on your Windows system.

Step 8: Complete the Installation

Once you complete the Node.js installation on your system, click ‘Finish’ to close the Node.js setup wizard.

how to check node version [step-by-step guide]

With Node.js installed, you can now verify to get Node version. Open the command prompt and enter:

> node --version 

how to check node version [step-by-step guide]

Alternatively, use: 

> node -v     

Both commands will display the installed Node.js version on your Windows system.

How To Check Node Version Using Console.Log? (Process.Version Property)

Once you install Node.js on your system, you can check the current Node release using the process.version property. To check Node version using console.log, type the ‘node’ command on the command prompt and then execute the following statement:

> node

The above command will open the Node terminal on the command prompt. Now, check the currently installed Node.js version:

> console.log(process.version)

how to check node version [step-by-step guide]

Alternatively, you can also directly get the node version at runtime using the built-in ‘process.version’ property:

> process.version

how to check node version [step-by-step guide]

You can get the versions of Node modules, including all dependencies, using the ‘process.versions’ property. Run this command on the command prompt:

> process.versions

The above command will return an object that will contain information about versions of the Node.js module and Node dependencies.

how to check node version [step-by-step guide]

  

How To Manage the Node.js Version Using NVM?

You can install Node.js on your Linux system using NVM (Node Version Manager). To do this, download the bash script file on your Linux system:

$ curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.1/install.sh | bash

how to check node version [step-by-step guide]

Source the downloaded bash script:

$ source ~/.bashrc

Now, list the available Node.js —versions using the nvm command:

$ nvm list-remote

how to check node version [step-by-step guide]

Choose the latest or specific Node.js version and install it running the below command:

$ nvm install v20.5.1

how to check node version [step-by-step guide]

Check Node.js version, which is currently installed on your Linux system.

how to check node version [step-by-step guide]

Conclusion

Throughout this guide, we delved into methods to determine the Node.js version on both Linux and Windows platforms. We explored the direct approach using the node version command node —version or node -v, as well as retrieving the Node.js version at runtime with the integral process.version property.

Node.js stands out in the tech ecosystem, not merely for its versatility but also for its distinctive advantage of harnessing JavaScript on both the front end and back end. Its prowess is evident in its widespread adoption for creating web servers, real-time applications, APIs, streaming services, chat interfaces, and a plethora of other applications.

So, having a firm grasp of Node.js and its intricacies is pivotal for modern developers aiming to produce efficient and responsive web applications.

how to check/intstall node js version

Node.js is a popular, open-source runtime. It lets programmers run JavaScript code outside a web browser. Developers use it to create servers, command-line tools, and web applications. Your version of Node.js, like any program, matters. It can affect your code’s performance and available features. To create adaptable, high-performance web applications using JavaScript, install Node.js on Ubuntu.

This blog will show you how to use the command line to find the version of Node.js installed on your computer. We will see how to check the Node.js version on Linux and Windows. It will be a detailed guide. You will get a clear idea of how to check the Node version.

Version Checking for Node.js

Step 1: Open a Terminal or Command Window

Open your terminal or command prompt as a first step. There are various approaches to doing this, depending on your operating system. On Windows, press the Windows key + R. Type “cmd” and hit Enter to open the command prompt. On macOS, access the terminal by clicking Terminal in Applications, then Utilities.

Step 2: Enter the Command to Check the Version of Node.js

Open your terminal or command prompt, then type and hit Enter the following command: in which -v stands for version.

node -v

Step 3: Look at the Node.js Version

Node.js will output its version number to the console after the command has been executed. It will look or appear something like this below:

v14.17.0

You can see that you are using Node.js version 14.17.0 from this. Your system may use a different version number than the one shown here.

Alternatively, you can use the command below to view additional details about the Node.js version:

node --version

How Do I Check the Version of Node? [Version Check Node.js]

Installing Node.js on many platforms is possible because it is cross-platform software. It has undergone many updates with cutting-edge tools and technologies. On Linux, macOS, and Windows operating systems, you can install and verify the version of Node.js.

You can find instructions on how to check the installed Node version here. It also has guides for installing Linux, Windows, and macOS.

Installation guide on Linux to check the version of node.js

Here, Ubuntu is being considered as a Linux distribution. The Ubuntu repository contains Node.js, which is simple to locate and install using commands. To verify the node version on a Linux VPS as well, adhere to the instructions below:

Step 1: To install Node.js, type this command in the terminal on your computer by pressing the keys ctrl+alt+t.

sudo apt install nodejs

guide to install nodejs version

Step 2: Use the following node version command to verify the Node.js version you installed after the first step.

node -v or node –version

check node version command

Step 3: Installing Node.js along with the Node package manager is strongly advised. You can access the Node.js packages’ open-source library with NPM. To install NPM, use the steps listed below.

sudo apt install npm

-v or npm –version

Installation Guide & Checking Node.js Version on Mac

The steps listed below can be used to install Node.js on macOS.

Step 1: Select macOS on the Node.js official download page.

Step 2: Launch the Node.js.pkg installation that was downloaded.

Step 3: After the download is complete, launch the installer, agree to all the terms, and select Install to complete the process.

Step 4: After the installation is finished, you will find the Node version installed on your machine.

Run this nodejs command. To determine the Node.js version, use the get version command.

$ node -v

check node js version command

Installation Guide on Windows to Check the Node Version

You need administrative permissions on your user account and the command line to install Node.js on a Windows computer. If you wish to install and test the Windows version of Node.js, follow the instructions below.

Step 1: Open the Node.js official download page and click the Windows installer link. By default, it will begin downloading the most recent version. An NPM package manager is included with the NPM installation.

Step 2: Launch the installer after the download is finished. Open the directory where your downloaded files are kept.

Step 3: Confirm your decision to execute the software by clicking execute when prompted.

Step 4: You will be added to the Node in this step. Js setup wizard, then select Next.

Step 5: After agreeing to the terms and conditions, you will be asked to accept the license. Click Next to begin the program installation.

Step 6: When prompted, choose to leave the default location for the software or enter the correct path, then click Next.

Step 7: Next, choose the elements you want to include and don’t want to include as necessary, then click Next.

Step 8: Finally, you can select Install to launch the installer and select Finish.

You may check the Node.js version that is installed by entering the following command at the command prompt.

node –v

check installed node js version

Advantages of Node.js

  • High Performance: Developers designed Node.js for fast, scalable performance. The renowned Chrome V8 JavaScript engine, which is quick and efficient, serves as the basis for it. Node.js uses a great event-driven, non-blocking I/O mechanism. It lets it handle many concurrent connections.
  • Many Node.js packages and modules make it easy to use third-party libraries for various tasks. The Node Package Manager (npm) has over a million packages. They range from database drivers to web frameworks.
  • Node.js is easy to learn. It uses JavaScript, a popular programming language. Many people use it worldwide. If you know JavaScript, learning Node.js will be easy. You can then start creating apps right away. The syntax of JavaScript is simple to learn and comprehend, even if you are a beginner.
  • Cross-Platform Compatibility: Node.js works with Windows, Linux, and macOS. You can create apps on any platform and run them anywhere without changes.
  • Microservice Architecture: Use Node.js to create small, independent services. They should work together to build a larger app. This method makes it easy to scale and maintain large, complex programs.
  • Node.js is great for real-time apps, like chat programs, online games, and live streaming. It can manage many connections at the same time and send data with no delay.
  • Community Support: Node.js has a large, vibrant developer community. They advance the platform and support each other. The community updates and improves Node.js regularly. Each release boosts its robustness and features.

Final Thought on How to Check Node Version

In summary, Node.js has many advantages. It makes it perfect for building scalable, high-performance, real-time apps. Developers like it for its ease, cross-platform support, and vast package ecosystem.

Node.js is a strong, popular framework for server-side apps. High performance, a diverse ecosystem of packages, and an understandable syntax. It has many advantages. They include cross-platform interoperability, a microservices architecture, real-time apps, and community support. Developers can build strong, scalable apps that meet today’s needs. They can take advantage of these benefits to meet both organizations and customers.

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