cdnjs

cdnjs.cloudflare.com serves 33 of the 34 libraries in this index with a url that has been verified. Its url shape is https://cdnjs.cloudflare.com/ajax/libs/<library>/<version>/<file>.

What cdnjs is good at

Curated, served by Cloudflare, and the only one of the three that publishes an SRI hash for the files it hosts. If you want subresource integrity without computing it yourself, this is the one to use.

What catches people out

It carries a curated subset rather than all of npm, and it sometimes republishes packages under its own version numbering — it lists Prism under a version that has never existed on npm. A cdnjs version number will not reliably work on another provider.

Questions

Which CDN should I use?

cdnjs if you want an SRI hash without computing one. jsDelivr if the package is on npm but not on cdnjs, or if you want a version range. unpkg if you need to reach one specific file inside a package. For anything real users will load, prefer the url you have actually fetched — which is why the last-checked date is on every one of them.

Are these URLs actually checked?

Yes, and that is the whole point of this site. Every url here was requested and the answer recorded — 100 of 102 responded successfully at the last check on 2026-09-03. A url we could not verify is labelled unverified rather than presented as working, and a url that failed says so along with how long it has been failing.