The five things slowing down almost every WordPress site

When a client tells me their WordPress site is slow, the theme gets blamed first. In most audits it is not the theme. Here is the order I check things in.

1. Hosting and PHP version

Cheap shared hosting with an old PHP version will cap every other fix. Moving to PHP 8.2+ on decent hosting is often a 30 to 40 percent improvement on its own.

2. Images

Unresized uploads straight from a phone camera are the most common problem I see. Serve WebP or AVIF, set width and height attributes, and lazy-load anything below the fold.

3. Plugins that load everywhere

A contact form plugin that loads its scripts on every page, a slider used on one page that loads on all of them. Audit with Query Monitor and unload per page.

4. Third-party scripts

Chat widgets, heatmaps and three different analytics tags. Each one costs main-thread time. Delay them until user interaction.

5. Caching that is not configured

A caching plugin is installed but page cache is off, or the CDN is caching nothing. Check the response headers, not the settings screen.

Fix them in this order. Each step makes the next one easier to measure.