WordPress can be very fast or very slow. The difference is almost always caching, images, and how many plugins load scripts on every page. Test your site, then work down the list.
Runs Google Lighthouse on mobile and desktop at the same time, plus real-user Chrome data. Takes about 20–40 seconds.
You control almost everything on WordPress: hosting, caching, theme and plugins. That means more ways to break speed, but also more ways to fix it. Each fix below lists the metric it usually moves; check that metric in your test result to pick where to start.
Without a cache, PHP and the database rebuild every page on every visit. Use your host’s built-in cache, or a plugin such as WP Rocket, LiteSpeed Cache (on LiteSpeed servers) or W3 Total Cache. Put a CDN in front for visitors far from your server.
WordPress creates resized copies and adds srcset automatically since version 4.4, so upload sensibly sized originals and let it do its work. Convert to WebP or AVIF (supported in core uploads since 5.8 and 6.5) or use an image plugin or CDN.
Since WordPress 5.5, images get loading="lazy" by default, and since 6.3 core skips the first large image and adds fetchpriority="high". Page builders and sliders can undo this, so check the LCP element in the speed test.
Each plugin can add CSS and JavaScript to every page, even where it isn’t used. Remove what you don’t need, and use an asset manager (e.g. Perfmatters or Asset CleanUp) to unload scripts on pages that don’t use them.
Caching plugins can defer or delay scripts and remove unused CSS. Turn the options on one at a time and test, as delaying jQuery can break themes and forms.
Heavy multipurpose themes and page builders ship a lot of CSS and JS. Block themes and lightweight themes start much leaner.
Newer PHP versions are markedly faster than old ones. Run a supported PHP version, and move off overloaded shared hosting if server response stays slow after caching.
Chat widgets, social feeds, YouTube embeds and multiple analytics tags are frequent culprits. Load them on interaction (click to load) or remove them.
For platform-independent fixes, see the speed optimization checklist, and check page weight with the page size checker.
The usual causes are no page caching, oversized images, too many plugins loading scripts site-wide, a heavy theme or page builder, and slow shared hosting. The speed test shows which one applies to your page.
There is no single best one; a page caching plugin that suits your host is the most important. Many managed hosts include caching, in which case a separate caching plugin can conflict. Add an image optimisation tool and, if needed, an asset manager.
Quality matters more than count. One badly built plugin that loads large scripts on every page can do more harm than ten small, well-built ones. Check which files load on your page in the speed test.