How to Install and Use Node.js & npm on Debian & Ubuntu

Node.js is a JavaScript runtime built on Chrome’s V8 engine that allows you to run JavaScript on the server side. npm is the default package manager for Node.js. This guide covers installing and using Node.js and npm on Debian and Ubuntu.

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Check Current Node.js Version

Check if Node.js is already installed:

node --version
node -v
npm --version
npm -v

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Method 1: Install from Debian Repository (Easiest)

Step 1: Update Package Lists

sudo apt update

Step 2: Install Node.js

sudo apt install -y nodejs

Check versions:

node -v
npm -v

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Method 2: Install Using NodeSource Repository (Recommended)

Install specific Node.js versions (20.x, 18.x, 16.x):

Step 1: Add NodeSource Repository

For Node.js 20.x (LTS):

curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash -

For Node.js 18.x:

curl -fsSL https://deb.nodesource.com/setup_18.x | sudo -E bash -

Step 2: Install Node.js

sudo apt install -y nodejs

Step 3: Verify Installation

node -v
npm -v

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Method 3: Install Using nvm (For Multiple Versions)

nvm allows you to manage multiple Node.js versions:

Step 1: Install nvm

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash

Step 2: Configure nvm

Add to ~/.bashrc:

export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
[ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion"

source ~/.bashrc

Step 3: Install Node.js Versions

nvm install 20
nvm install 18
nvm install --lts

nvm Commands

• List installed versions: nvm list
• Use specific version: nvm use 20
• Set default version: nvm alias default 20
• Uninstall version: nvm uninstall 18

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Using Node.js

Run JavaScript File

Create a test file:

nano hello.js

console.log("Hello, World!");

const add = (a, b) => a + b;
console.log("2 + 3 =", add(2, 3));

const os = require('os');
console.log("Platform:", os.platform());

node hello.js

Start REPL

Interactive Node.js console:

node

REPL commands:

• .help – Show help
• .clear – Clear context
• .exit – Exit REPL

Simple HTTP Server

const http = require('http');

const server = http.createServer((req, res) => {
  res.writeHead(200, { 'Content-Type': 'text/plain' });
  res.end('Hello from Node.js!');
});

server.listen(3000, () => {
  console.log('Server running at http://localhost:3000/');
});

node server.js

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Using npm – Package Manager

Initialize a Project

Create package.json:

npm init -y

Install a Package

npm install lodash

Install as Dev Dependency

For development only (testing, etc.):

npm install --save-dev jest

Install Global Package

Available system-wide:

npm install -g pm2

Uninstall Package

npm uninstall lodash

List Installed Packages

npm list

List Global Packages

npm list -g --depth=0

Update Packages

npm update

Run Scripts

Run scripts from package.json:

npm run build
npm run dev
npm start
npm test

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Common npm Packages

• express – Web framework
• react – UI library
• vue – Progressive framework
• lodash – Utility library
• axios – HTTP client
• nodemon – Auto-restart server
• pm2 – Process manager
• typescript – TypeScript compiler
• jest – Testing framework
• webpack – Bundler

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Example: Express Web Server

mkdir myapp
cd myapp
npm init -y
npm install express

nano index.js

const express = require('express');
const app = express();
const port = 3000;

app.get('/', (req, res) => {
  res.send('Hello from Express!');
});

app.listen(port, () => {
  console.log(`Server at http://localhost:${port}`);
});

node index.js

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npm Commands Reference

• npm install package – Install package
• npm install package@version – Install specific version
• npm install -g package – Install globally
• npm uninstall package – Remove package
• npm list – List packages
• npm update – Update packages
• npm search package – Search packages
• npm docs package – View docs

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Troubleshooting

npm: command not found

Reinstall Node.js and npm:

sudo apt remove --purge nodejs npm
sudo apt autoremove
sudo apt install -y nodejs

Permission Errors (EACCES)

Fix npm global directory:

mkdir ~/.npm-global
npm config set prefix '~/.npm-global'

echo 'export PATH=~/.npm-global/bin:$PATH' >> ~/.bashrc
source ~/.bashrc

Slow npm Install

Use a different registry:

npm config set registry https://registry.npmmirror.com

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Conclusion

You now have Node.js and npm installed! Key commands to remember:

• node file.js – Run JavaScript file
• npm install package – Install package
• npm install -g package – Install globally
• npm init -y – Create package.json
• npm run dev – Run dev script