How to speed up a website: the fixes that matter

With a measurement. Run your home page and your most important pages through PageSpeed Insights, on mobile, and note the three Core Web Vitals and the top issues in the diagnostics.

If you're not sure what's causing the slowness, start with our guide to why websites are slow. This page is the fix list, in the order that usually makes the biggest difference.

Work down the list. Re-test after each change, so you know which one helped.

1. 1Resize images to the size they're shown at, and convert them to WebP or AVIF.
2. 2Add width and height to images and video, so the page doesn't jump as they load.
3. 3Lazy-load images further down the page, but never the main image at the top.
4. 4Remove scripts you don't use: old tracking pixels, chat widgets nobody answers, heatmaps from a past project.
5. 5Load the scripts you keep after the main content, or only on the pages that need them.
6. 6Turn on page caching, so the server isn't building every page from scratch.
7. 7Serve the site through a content delivery network, so files come from a server near each visitor.
8. 8Cut web fonts to the weights you actually use, host them yourself and show fallback text while they load.
9. 9Replace autoplaying video at the top of the page with a still image that plays on tap.
10. 10Remove plugins you don't need, and update the rest.
11. 11If the server is still slow to respond, move to better hosting.

Make them smaller, in every sense. Images are the heaviest thing on most pages, and the fix is quick.

• Resize before upload. A photo straight from a phone is often several times wider than any screen shows it.
• Use modern formats. WebP and AVIF are usually much smaller than JPEG or PNG at the same quality.
• Use responsive images, so phones get a smaller file than large desktop screens.
• Give the main image at the top of the page high priority, and lazy-load the rest.
• Use simple graphics as SVG rather than large image files.

Audit them, then remove or delay as many as you can. Every chat widget, tracker, review badge and social embed loads its own code, and many slow down how quickly the page responds to a tap, which is what Interaction to Next Paint measures.

List every script on the site and ask who uses its data. Anything nobody looks at can go. For the rest, load them after the main content, or only on the pages that need them. A chat widget on the contact page alone is often enough.

It fixes slow server responses, and that's all. Check the server response time in PageSpeed Insights. If it's slow, better hosting and caching will help every page. If it's quick, the problem is in the site, and moving host won't change much.

A content delivery network helps either way, because it puts copies of your files close to every visitor.

Reserve space for everything before it arrives. That's what Cumulative Layout Shift measures, and it's one of the most annoying things for visitors.

• Set width and height on every image, video and embed.
• Give ad slots, cookie banners and embeds a fixed space.
• Use fallback fonts that are close in size to your web font.
• Don't insert banners above content that has already loaded.

The same fixes, plus a few specific to WordPress. Use a caching plugin or host-level caching, remove plugins you don't use, choose a lightweight theme, and be wary of page builders, which load a lot of code on every page. Keep WordPress, the theme and plugins updated.

If the theme or page builder is the problem, each fix gets harder. At that point a move to a modern, hand-coded site can cost less than years of patching.

Check it every month. Sites slow down gradually, as new images, plugins and tracking tags get added. A monthly check in PageSpeed Insights and Search Console's Core Web Vitals report catches problems before visitors notice them.