Every page load unserialising four hundred kilobytes of a plugin’s cached API response, because it had been stored as an autoloaded option. Autoloaded options are read as one…
A hero image uploaded at 6000 pixels wide, served at 1200, on every page load, for eleven months. WordPress has scaled large uploads down since 5.3 and a…
The block editor fetches patterns from a remote directory, which is a network request on an admin page load and a dependency on somebody else’s uptime. On a…
Every autoloaded option is fetched and unserialised on every request, and a plugin storing a large structure in one turns a cache into a fixed cost. Tracking the…
The object cache API is always available and, without a drop-in, discards everything at the end of the request. Within a request it is still worth having —…
6.0 shipped a webfonts API, deprecated the PHP registration form during the release cycle, and settled on declaring fonts in theme.json. WordPress generates the @font-face rules and a…
Layout shift is nearly always an element that reserved no space and then took some, and images are the largest single cause. Browsers compute an aspect ratio from…
A lab tool measures one load on one connection, and the metric that counts is the 75th percentile of real visitors over 28 days. First Input Delay cannot…