Speed up a slow WordPress site

A slow site drives visitors away and drops in Google results, which takes loading speed into account (the Core Web Vitals). The good news: most slowdowns come from a handful of well-known causes that are easy to fix. This guide shows you how to measure your site's speed, then how to improve it, from the most effective actions to finer tuning.

Before you start

• Create a backup of your site, see Restore a backup of your website: some optimizations change the database or files.
• Write down your starting score so you can measure the effect of each action.
• Make one change at a time and test your site after each one.

Measure your site's speed

Open your hosting, choose your site in Your WordPress sites, then the Performance tab. Click Analyze with PageSpeed: you get a desktop score and a mobile score. You can also use Google PageSpeed Insights directly on the web.

Focus on three metrics:

• LCP (Largest Contentful Paint): how long the largest element on the page takes to appear, often an image. Aim for under 2.5 seconds.
• INP (Interaction to Next Paint): how quickly the page responds when someone clicks.
• CLS (Cumulative Layout Shift): how much the layout jumps around while loading.

Speed up WordPress step by step

1. Open your site in Your WordPress sites, then the Performance tab.
2. Run Analyze with PageSpeed and note the mobile score.
3. In Cache management, check the cache status, then click Clear all after any major change.
4. In Database optimization, click Optimize now to optimize tables, delete revisions and clean up transients.
5. In Image optimization, convert your images to WebP.
6. In WordPress, deactivate and then delete unnecessary plugins.
7. Check that your site runs a recent PHP version, see Change the PHP version.
8. Run the analysis again and compare with your starting score.

Why do images slow sites down so much?

A photo uploaded straight from a phone often weighs several megabytes, while a 200 KB image is plenty on screen. Three habits help:

• Resize images before uploading them: 1920 pixels wide is enough for a full-width image.
• Convert to WebP, a format lighter than JPEG at the same quality.
• Use lazy loading: images further down the page only load when the visitor scrolls. WordPress already does this by default for most images.

How does caching work?

Without a cache, WordPress rebuilds every page on every visit: it runs PHP and queries the database. With a cache, the already built page is served directly. There are several layers:

• OPcache keeps compiled PHP code in memory;
• Object Cache keeps the results of database queries;
• page cache keeps the final HTML page.

Upkyo WordPress hosting plans include AccelerateWP, which is designed to speed up your pages. Avoid stacking several caching plugins: they get in each other's way and can slow the site down instead of speeding it up.

Plugins and theme

Each plugin adds code, sometimes with scripts and stylesheets loaded on every page. Quality matters more than quantity. Clean up:

• delete the ones you no longer use;
• replace heavy plugins that do one small task;
• prefer a lightweight theme to "all-in-one" themes packed with options and animations;
• limit web fonts, background videos and sliders.

The database

Over time, the database collects post revisions, auto-drafts, spam comments and temporary data (transients). The Optimize now button in the Performance tab does this cleanup. Do it after a backup, for example once a month.

What if the site is still slow?

• Test with the default WordPress theme and plugins deactivated to find the culprit.
• Check the error logs (Logs, then Error logs): repeated errors slow every page down.
• If your site has grown a lot, move to a higher plan, see Change plan.
• Open a ticket from /submitticket.php or email support@upkyo.com: a technician can look at your site.

Frequently asked questions

Why is my WordPress site so slow?

The most common causes are heavy images, too many plugins, no caching and an old PHP version. A PageSpeed analysis shows what weighs most on your page.

How do I test my WordPress site speed?

Use Analyze with PageSpeed in your site's Performance tab, or Google PageSpeed Insights. Look at the mobile score first, since Google uses it for ranking.

Do I need a caching plugin?

One is enough, and sometimes none is needed if your hosting already provides caching. Running several caching plugins at once creates conflicts.

Can clearing the cache break my site?

No. Clearing the cache only deletes temporary copies, which are rebuilt on the next visits. The first visit after clearing is simply a little slower.

Does a newer PHP version make WordPress faster?

Yes, recent PHP versions run code faster. Just check that your plugins are compatible before switching, see Change the PHP version.