Install Node.js modules

Node.js comes with the npm package manager. Using it, you can install, uninstall and search for Node.js modules.

npm installs modules in two different scopes: local and global.

Local installation

The local installation is recommended, as the size of the packages is usually small. It installs the packages in a node_modules subdirectory of the current working directory, usually a project folder. This ensures all the required dependencies are installed and won’t break when installing other packages in a different project or locally.

To install modules locally, you just have to execute this command:

$ npm install PACKAGE

For example, to install MySQL, you would execute:

$ npm install mysql

Global installation

In other cases (typically when the module installs a command line tool), it is more convenient to install the packages globally. In these cases, the command varies slightly:

$ sudo npm -g install PACKAGE

For example, to install Express, you would execute:

$ sudo npm -g install express

This will make the Express command-line available in all projects.

We recommend installing packages in both local and global modes, so that you can share installed commands and still protect the dependencies of your project.