All these: https://developers.google.com/speed/docs/mod_pagespeed/filters https://developers.google.com/speed/docs/mod_pagespeed/filte... So image optimization

All these: https://developers.google.com/speed/docs/mod_pagespeed/filters https://developers.google.com/speed/docs/mod_pagespeed/filte... So image optimization, css and js minification, cache extension, css combining, image spriting, ... But offloading things to CDN is actually one of the things it doesn't do. You might be thinking of the PageSpeed Service [1] which is a Google-hosted version. [1] https://developers.google.com/speed/pagespeed/service https://developers.google.com/speed/pagespeed/service