How do I check if a site has a cdn?
In order to check if AWS Cloudfront (CDN) is being used, just look for an x-cache response header. It will say have a mention of the Cloudfront (ie. Hit from Cloudfront or Miss from Cloudfront). Example:
1) To view this go to the web-page and right click -> Inspect (or hit f12)
2) Select the Network tab
3) If the main page isn't there, refresh the page
4) Select the page you want to check