cdnjs is a free, open-source content delivery network (CDN) for JavaScript libraries, CSS frameworks, and web fonts, hosted by Cloudflare. Launched in 2011, it has become one of the largest and most popular public CDN services, serving billions of requests daily. cdnjs hosts over 4,000 libraries including jQuery, React, Vue, Bootstrap, Font Awesome, and virtually every popular frontend library. The CDN provides automatic updates, version management, and fast global delivery through Cloudflare's extensive edge network. All resources are served over HTTPS with SRI (Subresource Integrity) hashes for enhanced security. Using cdnjs can improve page load performance through parallel downloads, browser caching across sites, and reduced server load. The service is community-driven, with contributions managed through GitHub, and offers API access for programmatic library searches.

Live sites
765.6k
Current snapshot
Market share
5.7%
Of tracked domains
Rank
#4
In CDN
Adoption history
Monthly detection · 1Y
Jul 2026 · 570,930 sitesAug 2026 · 571,453 sitesSep 2026 · 571,847 sitesOct 2026 · 753,873 sitesNov 2026 · 763,980 sites763,980 0 Jul 2026Aug 2026Sep 2026Oct 2026Nov 2026

Series filtered to 5 data points · monthly snapshots since July 2026.

Counts follow the sites we crawl. Our crawl grew sharply in October 2026, so part of that month's rise reflects coverage, not adoption.