npm
An exact package-name lookup against the npm registry.
Package name checker · exact lookups
Find out who already has the name, before you publish.
A taken package name is cheap to discover now and expensive to discover after the README, the docs and the first release. NamingSignal checks the exact name against npm, PyPI, GitHub and the Apple App Store, and reports what each source actually said.
npm: taken (registry.npmjs.org, 2026-11-05)
pypi: available (pypi.org, 2026-11-05)
github: taken (api.github.com, 2026-11-05)
apple: unknown (rate limited, 2026-11-05)PyPI
An exact project lookup against the PyPI JSON API.
GitHub
An exact account and organization name lookup against the GitHub REST API.
Apple App Store
An exact app-name lookup against Apple's public search endpoint.
What is not checked
Stated, not implied
crates.io, Maven Central, NuGet, RubyGems, Docker Hub, Google Play and the Chrome Web Store have no automated checker here. They are reported as manual work rather than quietly counted as clear, because a missing check and a passing check are not the same answer.
Unknown stays unknown
A rate limit is not availability
When a registry times out, rate-limits or returns something unusable, the result stays unknown. Every other state carries the endpoint it came from and the time it was checked, so a stale answer is visible rather than assumed.
Beyond the registry
A free name can still be the wrong name
An unclaimed package name says nothing about a company, product or trademark already using it. The same check surfaces domains, same-category namesakes and hard blockers, and keeps those separate from the usability score.
Related
What actually kills a name.
Package collisions are one of five things that make a launched name expensive to keep.
Questions
Package name checker FAQ
How do I check if an npm package name is taken?
Enter the name and NamingSignal queries the npm registry for that exact package name, alongside PyPI, GitHub and the Apple App Store. Each answer carries the source it came from and the time it was checked, and a source that times out or rate-limits stays unknown rather than being reported as free.
Which package registries are checked automatically?
npm, PyPI, GitHub accounts and the Apple App Store. crates.io, Maven Central, NuGet, RubyGems, Docker Hub, Google Play and the Chrome Web Store are not checked automatically and are listed as manual work rather than silently treated as clear.
Does a free npm name mean the name is safe to use?
No. An unclaimed package name says nothing about an existing company, product, trademark or same-category competitor using the name. Package availability is one input; NamingSignal keeps hard collision signals separate from the usability score so a good average cannot hide a disqualifying conflict.
Can I check package names from Claude Code or Codex?
Yes. The same namespace checks run over the REST API, the local CLI and the MCP server, including a remote Streamable HTTP MCP endpoint that connects with one command and a free API key. An agent can check a name while scaffolding a project.
What does it cost?
A free NamingSignal account includes 15,000 Naming Credits a UTC month with the API, CLI and MCP server included and no card required. Namespace checks run alongside the domain check for the name they belong to.