cdnjs - The #1 free and open source CDN built to make life easier for developers | WarmIndex

cdnjs is a free, open-source CDN that hosts thousands of JavaScript, CSS, and front-end libraries to make web development faster and easier for developers worldwide.

🚀 Overview

cdnjs is the #1 free and open-source content delivery network (CDN) for open-source front-end libraries, powered by Cloudflare. It allows developers to quickly include popular JavaScript, CSS, fonts, and frameworks in their websites without hosting the files themselves, leveraging global edge caching for speed and reliability.

Founded in 2011 by Ryan Kirkman and Thomas Davis, it partnered with Cloudflare early on and fully transferred to them in 2019. Today, it's community-maintained with over 1,400 contributors and serves over 12.5% of all websites, handling 200 billion requests monthly.

What problem does this project solve? Hosting libraries locally wastes bandwidth, slows load times, and requires maintenance; cdnjs provides instant, cached delivery worldwide. Who is it built for? Web developers, frontend teams, and anyone building websites or apps needing third-party assets. Why did you build it? To simplify developers' lives by offering a reliable, free alternative to self-hosting or limited commercial CDNs.

✨ Key Features

Hosts 4,587+ popular libraries (e.g., jQuery, React, Bootstrap, Vue) with multiple versions, searchable via web or JSON API
Ultra-fast global delivery powered by Cloudflare with HTTP/2, HTTPS, SRI support, and automatic caching
Public JSON API (api.cdnjs.com) for querying libraries, versions, files, and metadata
Community-driven updates: auto-sync for npm/GitHub releases, manual PRs for others; experimental auto-updates

🛠 Tech Stack

Frontend: Vue.js, Nuxt.js, SCSS
Backend: TypeScript, Cloudflare Workers
Database: Cloudflare KV (for caching)
Auth: None (public API)
Hosting: Cloudflare

👥 Who Is This For?

This project is useful for:

Developers who want to quickly link to libraries without self-hosting
Teams looking for cost-free, high-performance CDN with massive uptime
Indie makers building web apps needing reliable asset delivery

📸 Screenshots / Demo

Live demo: https://cdnjs.com
GitHub: https://github.com/cdnjs

🔥 Project Status

🟢 Actively building

Last updated: 2026-03-24

❓ FAQ

Is this project free?

Yes — completely free for unlimited use, open source.

Is the source code available?

Yes — https://github.com/cdnjs (key repos: cdnjs/assets, packages/metadata, static-website, api-server)

Can I contribute?

Yes — submit PRs to https://github.com/cdnjs/packages for new libraries or updates. Robot builds assets automatically. See CONTRIBUTING.md for details; donations via Open Collective.