- Measure first with PageSpeed Insights, so you fix the actual bottleneck.
- Good hosting, a current PHP version and page caching fix the biggest share of problems.
- Resize and compress images, and use WebP or AVIF; WordPress supports both.
- Every plugin and script has a cost. Remove what you don't use and delay what isn't essential.
Why WordPress sites get slow
WordPress itself is reasonably fast. Sites slow down because of what's built around it: the hosting it runs on, the theme and page builder, the plugins added over the years, the images uploaded at full camera size, and the third-party scripts in the header.
The good news is that you can speed up WordPress a lot without touching code. The order matters: fix the biggest bottleneck first.
Step 1: Measure before you change anything
Run your homepage and a key service page through PageSpeed Insights on mobile. Note:
- Largest Contentful Paint (LCP): how long the main content takes to appear
- Interaction to Next Paint (INP): how responsive the page is
- Cumulative Layout Shift (CLS): how much the layout jumps
- Time to First Byte (TTFB), in the diagnostics: how long the server takes to respond
Take a screenshot so you can compare later. Our guide to Core Web Vitals explains what each metric means.
| If you see… | The likely bottleneck is… | Start with… |
|---|---|---|
| Slow server response (TTFB) on every page | Hosting, PHP or no caching | Steps 2 and 3 |
| Slow LCP with a large hero image | Images | Step 4 |
| Poor INP, lots of JavaScript | Plugins, page builder and scripts | Steps 5 and 6 |
| Poor CLS | Images without dimensions, banners, fonts | Step 7 |
Step 2: Fix hosting and PHP
- Check your PHP version (Tools, Site Health in WordPress shows it). Use a version that's still supported; newer versions are usually faster as well as more secure.
- Consider better hosting if the server is slow on every page even with caching. Cheap shared hosting is the most common root cause of slow WordPress sites. Managed WordPress hosting typically includes server caching and a CDN.
- Use a CDN (content delivery network) to serve images and files from servers near your visitors. Many hosts include one.
Step 3: Turn on page caching
Without caching, WordPress builds every page from the database on every visit. Page caching saves a ready-made copy and serves it instantly.
- Check whether your host already caches pages. If so, don't add a second page-caching plugin on top; they can conflict.
- If not, install one reputable WordPress caching plugin and turn on page caching. Most also offer browser caching and file optimisation.
- Exclude pages that must stay dynamic, such as forms with live data or logged-in areas. Test your contact form after enabling caching.
Step 4: Fix images
Images are usually the heaviest part of a page.
- Resize before uploading: a hero image rarely needs to be wider than the largest screen it's shown on. Uploading a 6,000-pixel photo straight from a camera is a common cause of slow pages.
- Compress and convert: WordPress supports WebP and AVIF uploads. An image optimisation plugin can compress and convert existing images in bulk.
- Lazy loading: WordPress adds lazy loading to images by default, which delays images further down the page. Make sure your main hero image isn't lazy-loaded, as that slows LCP.
- Avoid sliders for the hero area. They load several large images and often hurt both speed and conversion.
Step 5: Audit your plugins
Every active plugin can add database queries, scripts and styles, sometimes on every page.
- List your plugins and note what each one does.
- Deactivate and delete anything you no longer use. Unused plugins are also a security risk; see our website security checklist.
- Replace overlapping plugins: two SEO plugins, two form plugins, three sliders.
- Test suspects one at a time: deactivate a plugin on a staging copy and re-run PageSpeed Insights to see its effect.
Step 6: Tame the theme, page builder and scripts
- Heavy themes and page builders load a lot of CSS and JavaScript. If your theme is bloated, a lighter theme or the block editor may be part of your next redesign; in the meantime, use the builder's own performance settings to load only what each page needs.
- Third-party scripts (chat widgets, tracking pixels, embedded social feeds, video players) often cost more than anything on your own server. Remove unused tags from your tag manager, and delay non-essential scripts until after the page loads or until someone interacts.
- Fonts: use fewer font families and weights, and host them locally if your theme allows.
- Embedded videos: use a thumbnail that loads the player only when clicked.
Step 7: Fix layout shifts
- Make sure images have width and height set (WordPress does this for images inserted through the editor).
- Reserve space for cookie banners and announcement bars, or make them overlay the page rather than push it down.
- Avoid ads or embeds that load late into the middle of content.
Step 8: Keep the database tidy
Over years, WordPress builds up post revisions, spam comments, expired temporary data and leftovers from deleted plugins. Many caching and optimisation plugins can clean these up. Back up first.
Measure again
Re-run PageSpeed Insights on the same pages and compare with your screenshots. Search Console's Core Web Vitals report reflects real visitors over 28 days, so give it time to update.
Questions
Why is my WordPress site so slow?
Usually slow hosting, no page caching, large uncompressed images, too many plugins, a heavy theme or page builder, or third-party scripts. PageSpeed Insights shows which apply to your site.
What's the best WordPress caching plugin?
The best one is the one that matches your hosting. Check whether your host already provides caching first, and use one reputable caching plugin rather than several.
How do I speed up WordPress without a developer?
Update PHP through your host, turn on page caching, resize and compress images, delete unused plugins, and delay non-essential scripts. These steps need no code.
Do too many plugins slow down WordPress?
It's less about the number than what each plugin does. One badly built plugin can slow a site more than ten light ones. Test suspects by deactivating them one at a time on a staging copy.
Does a page builder slow down WordPress?
Page builders often add extra CSS and JavaScript. Use their performance settings, avoid unnecessary effects, and consider the block editor or a lighter theme when you next redesign.
Every guide is checked against the platform it describes before it’s published, and re-checked when the platform changes.