Use a Content Delivery Network in Joomla!

CDN for Joomla! rewrites matching local file URLs in rendered Joomla output so browsers request those files from your CDN hostname.
It does not upload or move files and it does not move the Joomla HTML page to the CDN. Your origin-pull CDN retrieves and caches files from the website origin.
Use any origin-pull CDN service that provides a hostname and can retrieve the same public file paths from your Joomla website.
CDN provider settings remain under your control, including the origin, HTTPS, cache lifetime, query-string handling, content types, CORS headers, purging, and security rules.
Configure and test the CDN service first, then enter its hostname in CDN for Joomla!.