How to Speed Up a WordPress Website

A slow website quietly costs you money. Visitors give up before your offer even loads, Google uses speed as part of how it ranks pages, and every enquiry form that times out is a customer you paid to attract who never got in touch. The good news: most WordPress speed problems come from a handful of familiar causes, and most of them are fixable.

This guide is written for business owners, not developers. We have ordered the fixes by how much difference they usually make, so you can work down the list and stop when you are happy. Every suggestion here is something we do ourselves when we optimise client sites.

First, measure properly

Before changing anything, get a baseline so you know whether your work paid off. Google's PageSpeed Insights is free and tests your live site against the same Core Web Vitals Google uses in ranking: LCP (how fast the main content appears), INP (how quickly the page reacts when someone taps) and CLS (how much the layout jumps around while loading).

Two practical tips: test your mobile score, not just desktop — that is where most visitors live and where problems show first. And run the test three or four times, because shared hosting can produce different results on each run. Write the scores down; you will want them later.

1. Fix your images (the usual culprit)

In our experience images are the single biggest cause of slow WordPress pages. A handful of photos uploaded straight from a phone camera can easily weigh more than everything else on the page combined. Work through this checklist:

• Resize before uploading. If an image displays at 800 pixels wide, do not upload a 4,000-pixel original. Resize it first.
• Serve modern formats. WebP typically weighs 30–60% less than the same JPEG at similar quality — and as we found optimising this very site, photos that are already well-compressed JPEGs sometimes beat WebP, so test rather than assume. Flat graphics and screenshots in PNG form almost always shrink dramatically.
• Compress what stays. Plugins such as ShortPixel, Imagify or Smush compress on upload and convert to WebP automatically.
• Lazy-load below the fold. WordPress has done this natively since 5.5, but themes and builders sometimes override it. Images below the visible screen should not load until the visitor scrolls.
• Set width and height attributes so the browser reserves space and the page does not jump as images arrive.

2. Check your hosting

If images are the most common cause, hosting is the most common limit. A £3-a-month shared hosting plan puts your site on a server shared with hundreds of others, and no amount of plugin tuning will make up for a slow server response. Two things matter here: the plan itself, and where the server sits relative to your customers — a UK-focused business serving UK visitors should generally host in the UK or Western Europe.

You can see your server's contribution in PageSpeed Insights: look at "Time to First Byte" or the server response time figure. If the server alone is taking the best part of a second before anything starts happening, upgrading hosting will do more than any plugin. It is also the least glamorous fix, which is exactly why it gets skipped.

3. Turn on caching

Without caching, WordPress rebuilds every page in PHP for every single visitor — fetching content from the database, assembling the template, then sending it. A caching plugin builds each page once and serves the saved copy to everyone after that, which is dramatically faster and lighter on the server.

WP Rocket (paid) and LiteSpeed Cache or W3 Total Cache (free) are all solid choices. Use exactly one cache plugin — two will conflict and can genuinely break the site. Turn on page caching and browser caching, and clear the cache after you make changes elsewhere.

4. Cut plugin bloat

Every plugin adds code to every page load, whether you are "using" it that day or not. Sites carrying 30 or 40 plugins almost always have dead weight. Open your plugin list and be honest: anything deactivated, duplicated or half-forgotten should go. Watch for duplication — two SEO plugins, two cache plugins, a page builder plus a separate slider plugin all stack up.

If you want to see exactly what is slowing a page down, the Query Monitor plugin shows per-plugin timing on a test page. Deactivate plugins one at a time on a staging copy and re-test; you will usually find one or two responsible for a disproportionate share of the load time.

5. Update WordPress, PHP and everything else

Each major PHP release brings real performance gains, and many hosting dashboards let you switch PHP versions in one click — yet plenty of sites still run years-old versions. Check yours under Tools → Site Health, and if you are not on PHP 8.x, plan the jump (test first if the site is old, since ancient plugins can break). While you are there, update the core, theme and plugins: updates regularly include performance fixes, and staying current is also your basic security hygiene.

6. Add a CDN

A content delivery network stores copies of your static files — images, CSS, JavaScript — on servers around the world and serves each visitor from the nearest one. For a UK business with local customers the gain is modest; for anyone selling nationally or internationally it is significant. Cloudflare has a capable free tier, and most good cache plugins integrate with it directly.

7. Audit fonts and third-party scripts

Two quieter time-thieves. First, web fonts: every font family and weight you load is a file the visitor must download, so four weights of two families is plenty for most brands. Second, third-party embeds — live-chat widgets, tracking tags, embedded social feeds and video players all add requests you do not control. Keep the ones that earn their place, and load the rest only on the pages where they are actually used.

When DIY is not enough

If you have worked through this list and the site is still slow, the remaining causes are usually structural — a heavy theme or page builder, a database that needs a proper clean-up, or hosting that has simply outgrown the business. That's the point where a professional pass pays for itself, particularly if the site generates leads or sales. Our website speed optimisation service covers the full audit-and-fix process, and if the underlying build is the problem, our WordPress development team can rebuild the parts worth rebuilding. And once the site is fast, a maintenance plan keeps it that way — speed decay is gradual, and regular updates are what prevent it.

Frequently asked questions