How to clean up node modules?

This article is based on Node v16.15.1 and NPM 8.11.0.

When building a Node.js application you install a various amount of npm modules, the package.json and node-modules folder grow. It is best practice minimizing the code you have to maintain, and this is also true for npm packages.

Clean up node_modules/ folder

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There are two ways to clean up the node_modules folder:

• Delete the folder and reinstall
• Use npm prune (starting with npm version 6)

Manually remove and reinstall

You could remove your node_modules/ folder and then reinstall the dependencies from package.json.

Remove all your packages (for Windows users: you can use Git Bash to run this command):

rm -r node_modules/

Install packages:

npm install

Remove extraneous packages with NPM prune

Synopsis: npm prune [[<@scope>/]<pkg>...] [--production] [--dry-run] [--json]

npm prune removes extraneous packages. If a package name is provided, then only packages matching one of the supplied names are removed. Extraneous packages are those present in the node_modules folder, but not listed as any package's dependency list.

You can provide the following flags:

• --production - If the --production flag is specified, or the NODE_ENV environment variable is set to production, the packages specified in your devDependencies will be removed.
• --no-production will negate NODE_ENV being set to production.
• --dry-run indicates that you don't want npm to make any changes and that it should only report what it would have done.
• --json changes that npm prune made or would have made with --dry-run are printed as a JSON object.

Extraneous modules are pruned automatically (normal operations), hence this command is only needed with the --production flag. Though, operation is not always normal as it should be and crashes and mistakes happen. The command npm prune can help clean up resulting garbage of crashes.

TL;DR

• npm prune removes not listed packages in the node_modules folder.
• The flag --dry-run is useful to see what would be removed.
• When crashes or mistakes happen, npm prune can help clean up any resulting garbage.

Thanks for reading and if you have any questions, use the comment function or send me a message @mariokandut.

If you want to know more about Node, have a look at these Node Tutorials.

References (and Big thanks):

NPM prune