Unused dependencies

One of Knip’s core features is finding unused dependencies in your JavaScript and TypeScript projects. And it comes with many more features to remove clutter and keep your projects in great shape.

Why are unused dependencies a problem?

Having unused dependencies in your package.json is an issue for various reasons:

• They might end up in the final production bundle, increasing size and load times for end users.
• They waste space in node_modules and add to the installation time of the project.
• They slow down tooling such as linters and bundlers that analyze dependencies.
• They are confusing and noisy in package.json.
• They cause unnecessary extra work when managing and upgrading dependencies.
• They can cause version conflicts with other dependencies in use.
• They can cause false security alerts.
• They might have restrictive licenses and make your project subject to theirs.
• They usually come with transitive dependencies that have the same issues.

How do I find unused dependencies?

Use Knip to find and remove unused dependencies. It also finds dependencies that are missing in package.json and has a lot more features to keep your JavaScript and TypeScript projects tidy.

It’s easy to get started and make package management easier and more fun!

How does Knip identify unused dependencies?

Knip works by analyzing package.json files, source code and configuration files for other tooling in the project to find unused and missing dependencies. Knip has many heuristics, plugins and compilers to fully automate the process.

Can Knip remove unused dependencies?

Yes, Knip can automatically remove unused dependencies installed by a package manager like npm or pnpm for you. Add the --fix argument to auto-fix and remove unused dependencies from package.json.

Can Knip detect missing dependencies?

Yes, Knip detects missing dependencies. It analyzes package.json files, and reports packages that are missing. They should be added to package.json to avoid relying on transitive dependencies that can cause version mismatches and breakage.

Does Knip work with monorepos?

Yes, Knip has first-class support for monorepos and workspaces. It analyzes all workspaces in the project and understands their relationship.

For instance, if a dependency is listed in the root package.json it does not need to be listed in other workspaces. Except if you enable --strict checking.

Does Knip separate dependencies and devDependencies?

Yes, Knip understands the difference between dependencies and devDependencies. It has a production mode to focus on production code only and find dead code and dependencies that would otherwise only be referenced by tests and other tooling. This allows you to remove both unused exported code and their tests.

Does Knip work with my package manager?

Yes, Knip works with any package manager: npm, pnpm, Bun and Yarn are all supported. It’s easy to get started with any package manager.