Lockfile Analyzer

Analyze an npm package-lock.json, yarn.lock, or pnpm-lock.yaml: total package count, duplicated package versions with who pulled in each, dev/prod split, registry breakdown, and the largest dependency subtree. All parsing happens client-side.

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Paste an npm package-lock.json, yarn.lock, or pnpm-lock.yaml to see duplicate-version packages, dev/prod split, and registry breakdown.

Supports npm package-lock.json (both lockfileVersion 1's nested tree and 2/3's flat packages map), Yarn Classic yarn.lock, and pnpm-lock.yaml. Yarn Berry (v2+) lockfiles are detected but not fully parsed. All parsing happens client-side — nothing is uploaded anywhere.

Lockfile Analyzer

Analyze an npm package-lock.json, yarn.lock, or pnpm-lock.yaml: total package count, duplicated package versions with who pulled in each, dev/prod split, registry breakdown, and the largest dependency subtree. All parsing happens client-side.

Common uses

  • Find duplicated package versions in a package-lock.json
  • Compare dev vs production dependency counts
  • See which packages pulled in a duplicated version

Also searched as

  • analyze package-lock.json online
  • find duplicate packages in package-lock
  • yarn.lock analyzer
  • pnpm-lock.yaml analyzer
  • count npm dependencies in lockfile
  • dev vs prod dependencies count
  • which package pulled in duplicate version
  • largest dependency subtree npm
  • lockfile registry breakdown
  • check outdated packages from lockfile
  • npm package install size from lockfile

Frequently asked questions

How do I find duplicated package versions in package-lock.json?

Paste or load the lockfile into the Lockfile Analyzer. It lists packages present in several versions and shows which packages referenced each version.

Does it support yarn and pnpm?

Yes, it handles npm package-lock.json, yarn.lock and pnpm-lock.yaml.

Can I see how many dependencies are dev versus production?

Yes, where the lockfile records it. The analysis shows total and unique package counts, the prod/dev split, a registry breakdown and, for npm lockfiles, the largest dependency subtree.

Can it check for outdated packages?

Yes, the Outdated tab checks the packages in your lockfile against the npm registry, and the Size tab checks install and gzip sizes for packages you pick.

Is my data uploaded to a server?

No. This tool runs entirely in your browser — your input is processed locally on your device and is never uploaded or stored on a server.