Cdnjs is a Cloudflare-hosted free and open-source software (FOSS) content delivery network (CDN). It serves 3,919 JavaScript and CSS libraries as of September 2020, which are publicly stored on GitHub.
It is used in millions of websites, or 11.2 per cent of Internet websites, making it JavaScript's second most popular CDN.
You can load library files on your websites quicker and easier with cdnjs. Both community and Cloudflare manage the infrastructure of cdnjs.