2.7. Resource compression

To reduce page weight, Plone automatically combines and compresses CSS and Javascript.

Javascript and CSS files typically constitut more than 80% of the initial page download in a site, resulting in slow first-load page renders and heavy bandwidth usage. The built-in compression in Plone reduces the size of these files by about 25% out-of-the-box, and up to 50% when maximum compression is enabled.