What is the `--save` option for npm install?

Naveera A.

The Problem

Some people use --save option when installing packages with npm. For example, it is common to see the following command:

npm install packagename --save

What does the --save option do? And why do some people never use it?

The Solution

npm or node package manager is a package manager for node.

When you download a package using the npm command, it installs the packages in the node_modules folder and adds the installed module as a dependency in your package.json file.

Prior to npm 5.0.0, npm installed the packages in node_modules but didn’t add them as a dependency by default.

If you wanted to save the module as a dependency in the package.json file, you had to do it using the --save or -S option.

As of npm 5.0.0, you no longer need to use this option. Now npm saves all installed packages as dependencies by default.

If you want to save a package as a development-only dependency, you can do so by using the --save-dev or -D flag.

A few other options are also available that allow you to control how a package is saved using npm install. You can read about them on the official docs.