The quick way to load a well-known library without bundling it. cdnjs is a free, open source CDN for popular JavaScript, CSS and font libraries, cached on Cloudflare's network. Its About page says Cloudflare operates it, sponsors cover the cost, and it serves more than 250 billion requests a month from over 330 edge locations. It also says 12.5% of all websites use it. Libraries are curated: the community adds them, and new versions are picked up automatically from npm and GitHub. I found no G2 or Capterra reviews. The Reddit evidence is mostly debate about public CDNs in general, including a post titled 'Public CDNs Are Useless and Dangerous' that names cdnjs and jsDelivr. It suits projects that need a well-known library from a shared URL, and suits private or custom builds less.
Free tier quotas
Price
Free
Content
JavaScript, CSS and font libraries
Traffic
More than 250 billion requests per month
Edge locations
Over 330, per the About page
Network
Cloudflare
Updates
New versions picked up automatically from npm and GitHub
License
Open source
Funding
Sponsors
Last sniffed Oct 3, 2026. Always confirm on the official pricing page.
👍 Good boy
+The About page says cdnjs is free to use, open source and community-driven, supported by sponsors.
+The site says Cloudflare operates it and caches resources on Cloudflare's network.
+The About page cites over 330 edge locations and more than 250 billion requests a month.
+New library versions are picked up automatically from npm and GitHub, so there are no manual uploads for each version.
+A r/firefox answer notes that many sites use libraries hosted on cdnjs because it can save bandwidth and may make loading faster.
+The site says 12.5% of all websites use cdnjs, which is a vendor claim I did not verify.
👎 Watch out
−Libraries are curated and the community adds them, so a library nobody has added is not available.
−The About page I read names no usage limits, uptime guarantee or support contract.
−A r/programming post titled 'Public CDNs Are Useless and Dangerous' says there is no benefit to loading a library from cdnjs. My excerpt of the argument was cut off.
−A r/firefox thread titled 'What is cdnjs and should I block it?' shows some visitors weigh blocking the domain.
−I found no G2, Capterra or Trustpilot reviews for cdnjs, so the quality evidence here is thin.
The catch
cdnjs is free and funded by sponsors, and the About page lists no paid plan, usage limit or support contract. The page I read says nothing about commercial use, so that field is marked unknown.
Only curated libraries are served. If your library is not on cdnjs, you need the community to add it, and you cannot upload your own private build.
Public CDN debate is real. A r/programming post argues there is no benefit to loading a library from cdnjs, and the argument was cut off in my excerpt. A r/javascript thread asks about Subresource Integrity as a safeguard. If you use cdnjs, add integrity hashes and keep a local fallback.
What’s included
✓Free public CDN
✓JavaScript, CSS and font libraries
✓Cloudflare network
✓Automatic version updates from npm and GitHub
✓Community-curated library list
✓Open source project
Free tier value
Generosity
A
Estimated value
Free CDN for curated libraries
Feature parity
One free service for curated libraries, with no tiers.
Screenshots
cdnjs homepage
Paid plans
Free, all users
The About page says cdnjs is free to use and supported by sponsors.
Paid plans, none listed
I found no paid tier, support plan or service level agreement on the About page.
Common questions
Is cdnjs free?
Yes. The About page says it is free to use, open source and supported by sponsors.
Who runs cdnjs?
The About page says Cloudflare operates it.
How do libraries get added?
The community adds them, and new versions are then picked up automatically from npm and GitHub.
Are there usage limits?
The About page I read names none.
Should I use a public CDN at all?
Opinion splits. A r/programming post titled 'Public CDNs Are Useless and Dangerous' argues against it. A r/firefox answer says many sites use cdnjs because it can save bandwidth and speed up loading.
Change history
Checked October 22, 2026
The About page lists cdnjs as a free, open source CDN operated by Cloudflare with more than 250 billion requests a month.
