Cache Manager

Caching is the difference between a site that feels instant and one that makes people wait, and it is also the most common reason a change you just made does not appear. Both facts come from the same mechanism: something between your database and the visitor is holding a copy.

The complication is that there is never only one cache. A WordPress page can be held in a page cache on the server, an object cache in front of the database, a browser cache on the visitor’s machine, and a CDN edge somewhere near them — four independent layers, each with its own idea of how long a copy stays fresh. Fixing “my changes are not showing” means knowing which one is answering.

These guides work through that stack. Setting caching up safely, deciding what must never be cached — carts, checkouts, logged-in sessions — and understanding the headers that control how long anything is kept. Then the optimisation layer that usually arrives with caching: minification, lazy loading, image formats, and the Core Web Vitals numbers those choices move.

A large group here covers breakage, because aggressive optimisation breaks things in specific, recognisable ways. A minified stylesheet that collapses a layout, deferred JavaScript that kills a menu, two caching plugins fighting each other, a CDN serving yesterday’s HTML.

Start with the explainer on how caching works if the layers are new to you. Almost every other article assumes you can tell them apart.