npm License Checker
Paste your package.json and see the license of every dependency, with copyleft and missing licenses flagged. Everything runs in your browser and you can export the list to CSV or Markdown.
Files are processed in your browser. Only package names and versions are sent to the public npm registry to look up their licenses.
How the license check works
The checker reads the dependencies from package.json and looks up each package in the public npm registry: its license, description and homepage. With package-lock.json it uses the exact installed version, without it the latest published one.
It lists the direct dependencies from package.json, which is what usually goes into an app's list of third-party components. Dev dependencies are left out unless you include them.
Frequently asked questions
How do I list the licenses of npm dependencies?
Paste package.json into the checker. It looks up each dependency in the npm registry, shows its license and lets you export the list to CSV or Markdown.
Which npm licenses need attention?
Copyleft licenses such as GPL, AGPL, LGPL and MPL come with conditions on sharing source code. Packages with no license or marked UNLICENSED need the author's permission. Permissive licenses such as MIT, Apache-2.0, BSD and ISC mostly require keeping the copyright notice.
Is my package.json uploaded anywhere?
No. The file is processed in your browser. Only package names and versions are sent to the public npm registry to look up their licenses.