Installing Node.js

To run JavaScript outside a browser you need Node.js on your machine. This lesson installs it, checks that the terminal can find it, and explains which release to pick.

The fundamentals lesson on editors, terminals and running code covers what a terminal is and how to open one. This lesson assumes you can open one and type a command.

Which version to install

Node.js numbers its releases with a major version: 22, 24, 26. Each major is in one of a few states:

• Current is the newest line. It gets new features first.
• Active LTS (long-term support) is a line that has been declared ready for general use and gets fixes for a long time.
• Maintenance LTS only receives critical fixes, until the line reaches end of life.

As of 14 October 2026:

This course uses Node.js 26. The examples were written and run on Node.js 26.11.1, and any 26.x release behaves the same. Everything in the core path also runs on Node 22 and 24, because the oldest supported line is 22. When a lesson needs 24 or 26, it says so on the page with a marker like Node.js 24+Requires Node.js 24 or later, so you can tell what will and will not work on your install.

If you only need one install, take the LTS release from nodejs.org. If you are reading this after 28 October 2026, that is Node 26. Before then, install 26 if you want to follow along exactly, or 24 if you prefer an LTS line today. Both work for this module.

Node.js 20 and older have reached end of life. Do not install them.

Install it

A version manager such as nvm or fnm installs several Node.js versions side by side and switches between them per project. It is optional for this course. It is worth learning once you maintain more than one project.

Check that it worked

Open a new terminal and ask Node.js and its package manager for their versions.

node --version
npm --version

v26.11.1
11.20.0

You should see a version that starts with v. Yours may be newer or older than the one above. Node.js 26.11.1 ships with npm 11.20.0. npm is the package manager that comes with Node.js, and a later module uses it.

If the terminal says command not found (or 'node' is not recognized on Windows), the usual cause is a terminal that was open before the install. Close it and open a new one. If that fails, the folder that holds node is missing from your PATH, the list of folders the terminal searches for programs. Running the installer again fixes it in most cases.

Ask a running program for its version

A program can report which Node.js is running it. The process object is provided by Node.js, and it has two properties that are useful right now: process.version, the version string, and process.versions, an object with the versions of the parts inside Node.js, including the V8 engine.

Create a file named versions_print.mjs:

console.log(process.version);
console.log(process.versions.v8);

Run it with node versions_print.mjs. The output depends on your install. On Node.js 26.11.1 it is:

v26.11.1
14.6.202.34-node.37

The second line is the V8 engine version, which tells you which language features your engine has.

A program can also check the version. This one reads the major number out of process.versions.node and compares it with 22:

const major = Number(process.versions.node.split(".")[0]);

console.log("Node 22 or newer:", major >= 22);

Node 22 or newer: true

split(".") cuts the text "26.11.1" at each dot into a list of three pieces, and [0] takes the first. Number(...) turns that text into a number, so the comparison is between numbers. major >= 22 is true or false. The numbers lesson and the coercion lesson cover numbers and conversions in detail.

Common pitfalls

• Using a terminal that was open during the install. It does not see the new PATH. Open a new one.
• Several Node.js installs. node --version tells you which one the terminal reaches. If it shows an old version after you installed a new one, an older install is earlier on your PATH.
• Running sudo npm to get past a permissions error. Fix the cause instead. A version manager keeps everything in your home folder.
• Picking a Current release for production. Up to Node 26, production applications should use LTS releases.

console.log(process.version.slice(1));

26.11.1

const major = Number(process.versions.node.split(".")[0]);

console.log("Node 26 or newer:", major >= 26);

Node 26 or newer: true

const parts = process.versions.node.split(".");

console.log("major:", parts[0]);
console.log("minor:", parts[1]);
console.log("patch:", parts[2]);

major: 26
minor: 11
patch: 1

Summary

• Install Node.js 26 (or the 24 LTS) from nodejs.org, then check it with node --version and npm --version.
• Production code belongs on an LTS line. From Node 27 the schedule is one major version a year.
• process.version and process.versions let a program report what it runs on.

Next: the REPL, scripts and the browser console.