1. CloudFlare (FREE)Their DNS is fast.
2. StackPath (30 days trial)Loved their caching
3. Staticaly (FREE)Host your GitHub, GitLab, Bitbucket code with Multi CDN, Staticaly also can serve your images fastest around the world by FREE.
4. Imgpx (FREE)CDN for images, serve your images with Multi CDN, Auto optimize your images to WebP format.
5. KeyCDN (Free Trial for 30 Days)Their caching is good, really fast, and I love it, you should try.
6. CDN77 (14 days trial)Loved their support and custom datacenter, their dashboard also cozy.
7. Fastly (FREE Test Up to $50 of traffic!)Fastly is my favorite, almost all of my work uses their services.
8. BunnyCDN (they really fast but only 14 days trial)
9. G-Core Labs (14 days for free)
10. jsDelivr CDN (FREE with Multi CDN for GitHub, NPM and WP Plugins)11. Rawgit (FREE CDN for GitHub only, StackPath network) 12. raw.githack.com (FREE CDN for GitHub only, CloudFlare network) 13. CDN.net (Free Trial for 30 Days) 14. Fly.io (Edge Application $25 of free credits) can be used as CDN 15. Netlify (FREE All-in-one platform for automating modern web projects, can host your GitHub pages, Gatsby site, Hugo CMS and many more). I will update about CDN again. Soon.
Wondering how I connect WordPress.com without connect to WordPress.com server directly? I use Fly.io16. Zeit.co (With their Now, you can upload your application and serve with CDN for Free as your application is Open Source). 17. Cachoid (FREE, Optimized Varnish Cache)