Why caching appears in Loupely captures #
Caching is one of the most common causes of diagnostic confusion in WordPress. A change you made isn’t visible because a cached version is being served. A checkout fails because a stale page is providing an expired security token. An email doesn’t fire because a cached confirmation page displayed before the order was fully processed. Understanding what caching layers exist and what each one can affect helps you interpret Loupely’s triage recommendations when they point to clearing cache.
Page caching #
Page caching stores a static copy of a page and serves that copy to subsequent visitors without running PHP or querying the database. It dramatically reduces server load but creates problems when dynamic content is served from a static copy. The checkout page should never be page-cached. A cached checkout page serves stale cart data, expired nonces, and outdated pricing to customers. Most caching plugins exclude the cart and checkout pages by default, but this exclusion can be accidentally removed during a plugin update or configuration change.
Object caching #
Object caching stores the results of database queries in memory (typically Redis or Memcached) so the same query doesn’t have to run against the database repeatedly. Unlike page caching, object caching is transparent to the user: the page renders normally from PHP, but some of the data it uses comes from memory instead of the database. Object caching rarely causes the kinds of visible failures that page caching does, but it can serve stale data when a database record is updated and the cache isn’t cleared.
CDN #
A Content Delivery Network (CDN) caches static assets (images, CSS, JavaScript) on servers geographically distributed around the world, serving them from the closest location to each visitor. CDNs improve page load speed but introduce a caching layer that can serve old versions of files after you update them. A CDN can also apply its own firewall rules that block WordPress’s REST API, loopback requests, or AJAX calls as suspicious automated traffic. When Loupely’s captures show REST API blocks or AJAX failures, a CDN firewall rule is often the cause.
Browser caching #
Browser caching stores a copy of page assets locally in the visitor’s browser for a set period. This is the layer that clearing your browser cache addresses. It’s the first thing to rule out when you’ve made a change and can’t see it. Browser caching affects what you see; it doesn’t affect the diagnostic data Loupely captures, which comes from the server side.