Read docs Updated 2026-06-16
What is CDNJS?
CDNJS is a public content delivery network that hosts a large collection of open-source JavaScript libraries and web assets.
It is useful for web developers and frontend projects that require reliable, fast access to common libraries without self-hosting.
What you can build with CDNJS
Include libraries without self-hosting
Link directly to stable versions of jQuery, Bootstrap, or Lodash in HTML files to avoid managing asset uploads and updates.
Improve page load performance
Serve JavaScript and CSS from CDNJS edge servers so visitors download popular assets from a nearby location instead of the origin server.
Pin exact dependency versions
Reference specific library releases (e.g., react@18.2.0) in production sites to guarantee consistent behavior across deploys.
Get started with CDNJS
- 1Visit cdnjs.com and search for the desired library
- 2Select the version and file (JS or CSS) needed
- 3Copy the HTTPS URL provided on the library page
- 4Paste the URL into a script or link tag in your HTML
- 5Test the page to confirm the asset loads correctly
CDNJS: pros & cons
Pros
- +No authentication or account required
- +HTTPS links available for all assets
- +Huge catalog of popular open-source libraries
- +Globally distributed CDN with good uptime
Cons
- –Only hosts libraries already added to the catalog
- –No control over update timing or removal of files
- –External dependency can affect site availability
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Frequently asked questions
A free public CDN that hosts JavaScript, CSS, and web assets so developers can link to them directly instead of hosting the files themselves.
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