About cdnjs

cdnjs is a free, open-source, and community-driven CDN that makes it easy to include popular web libraries in any project — no build step, no npm install, just a single script or link tag.

Launched in 2011, it is one of the longest-running and most popular public CDNs on the web. cdnjs believes in the power of open source, with all the package configurations and code behind the service available on GitHub.

While a CDN isn't the right tool for every occasion, when it is, we're here for you (and your agent).

Every file is served directly from Cloudflare's global network, ensuring fast response times for any assets included on your website, with full support for HTTP/3, HTTP/2, QUIC, and Brotli + GZIP compression.

cdnjs is HSTS preloaded, ensuring all requests are securely served over HTTPS, and Subresource Integrity (SRI) hashes are provided for all script and link tags to provide an additional layer of security.

cdnjs is different from some other public CDNs that support on-demand pull-through access to libraries. Instead, cdnjs is a curated CDN that only serves libraries that have been added to the service by the community.

Adding a library to cdnjs is straightforward: open a pull request in the cdnjs/packages repository with a small JSON file describing the library. Once approved and merged, cdnjs automation takes over — new versions are picked up automatically as they are published to npm or GitHub.

No manual uploads for each version, no waiting for a maintainer to cut a release. The ingestion pipeline checks for updates regularly and handles minification, compression, SRI hash generation, and publishing to the CDN automatically.

packages/m/my-library.json

{
  "name": "my-library",
  "filename": "my-library.min.js",
  ...
  "autoupdate": {
    "source": "npm",
    "target": "my-library",
    "fileMap": [{
      "basePath": "dist",
      "files": ["*.js"]
    }]
  },
  ...
}