npm-check-updates (ncu)

npm-check-updates upgrades your package.json dependencies to the latest versions while preserving your existing version-range policy (^17.0.2 → ^18.3.1). It only modifies package.json; the user must run their package manager's install command (e.g. npm install) to update package-lock.json and node_modules.

The CLI is exposed as npm-check-updates and the shorter ncu. The library is dual ESM/CJS, importable from Node.

When to reach for this skill

• Listing outdated dependencies in a project.
• Bumping versions in package.json to the newest available (dry run, interactive, or write to disk).
• Bulk-upgrading with filters, rejections, peer-dependency awareness, or engine constraints.
• Scanning monorepos (workspaces, --deep, custom globs).
• Safer upgrades via cooldown windows or the iterative --doctor mode.
• Driving ncu programmatically from a Node script or a .ncurc.* config.

Quick start

# Dry run: print upgrades without touching files.
ncu