Installing Node.js in Debian 9

Node.js is a runtime platform that brings JavaScript beyond the browser, turning it into a general-purpose language. It's widely used as a web server and also supports desktop app development via NW.js, AppJS, or Electron.

Update the package list and install curl:

sudo apt update
sudo apt install curl

Method 1. Installing via PPA

NodeSource maintains a Personal Package Archive (PPA) with up-to-date Node.js releases. Navigate to your home directory and download the setup script for the version you need:

cd ~
curl -sL https://deb.nodesource.com/setup_10.x -o nodesource_setup.sh

Review the script before running it:

nano nodesource_setup.sh

Run the script:

sudo bash nodesource_setup.sh

Once the PPA is added, install Node.js:

sudo apt install nodejs

Check the version:

nodejs -v

Expected output:

v10.20.1

The nodejs package already includes npm — no separate installation needed. Verify npm is available:

npm -v

6.14.4

To compile native packages, install build-essential:

sudo apt install build-essential

Method 2. Installing via NVM

NVM (Node Version Manager) lets you install and switch between multiple Node.js versions on the same machine — ideal when different projects need different runtimes.

Download the installation script:

curl -sL https://raw.githubusercontent.com/creationix/nvm/v0.35.3/install.sh -o install_nvm.sh

Review the script before running it:

nano install_nvm.sh

Run the installer:

bash install_nvm.sh

Load NVM into the current session:

source ~/.profile

Browse available Node.js versions:

nvm ls-remote

Install a specific version — for example, v12.16.3:

nvm install v12.16.3

Switch to it:

nvm use v12.16.3

Confirm the active version:

node -v

v12.16.3

List all installed versions:

nvm ls

Set a default version:

nvm alias default 10.20.1

This version will be used every time you open a new terminal session. You can also switch to it explicitly:

nvm use default

Managing packages with npm

Each Node.js version manages its own packages independently.

Install a package locally:

npm install express

Install a package globally (available to all projects using the same Node.js version):

npm install -g express

Link a globally installed package to a local project:

npm link express