Best practices for caching dependencies in GitHub Actions?

[canberkberen]

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I'm setting up CI pipelines using GitHub Actions. What are the best practices for caching dependencies (e.g. npm, pnpm, yarn) to speed up builds? Any real-world tips or examples?

[highpriv]

Here are some proven best practices for caching dependencies in GitHub Actions:

1. Use the official actions/cache action
   Always prefer actions/cache@v4 for better performance and stability.

2. Cache based on lock files
   Use package-lock.json, pnpm-lock.yaml, or yarn.lock in the cache key.
   This ensures correct cache invalidation when dependencies change.

3. Separate cache per OS and Node version
   Include runner.os and Node version in the cache key to avoid conflicts.

4. Cache the correct directories

   • npm: ~/.npm
   • yarn: ~/.cache/yarn
   • pnpm: ~/.pnpm-store

5. Restore cache before installing dependencies
   Make sure the cache restore step runs before npm install / pnpm install / yarn install.

6. Prefer pnpm for large monorepos
   pnpm with caching usually provides the fastest install times.

Example setup (npm):

• uses: actions/cache@v4
  with:
  path: ~/.npm
  key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}

This approach typically reduces CI build times by 50–80% in real-world projects.