Most slow WordPress sites were not built badly on purpose. They were built in the usual way, with a bought theme, a page builder and a plugin for every feature. This is the quickest way to get a site live, which is why it is so common.
We know this approach well, because we also built sites this way. For years, like many agencies, we used a page builder and added another plugin when a deadline was close. The site works on launch day. Problems develop gradually after that, and by the time anyone notices, the site is hard to fix without starting again.
This article covers what usually goes wrong, how to check your own site, and what changes with a lean rebuild.
The usual causes
A slow WordPress site rarely has one problem. It usually has several small problems that combine to slow it down.
Page builders
Page builders make it easy to lay out a page without writing code. The drawback is that every visitor downloads extra code. Builders wrap each element in extra layers of markup. They load their own scripts and styles on every page, whether that page uses them or not.
Builders also make the content hard to move. Layouts are stored as builder-specific data or shortcodes. If you stop using the builder later, you have to rebuild the pages.
Too many plugins
Every plugin adds code. Many plugins load their own scripts and styles on every page, run extra database queries and add screens to the admin area. One or two plugins cause no problems. Thirty or more, added over the years by different people, do cause problems.
Plugins are the source of most WordPress security problems. WordPress itself has fewer. More plugins mean more software to update and more that can fail. Each plugin is also a possible entry point for attackers.
Large themes
Multipurpose themes are built to suit any kind of site, so they come with many features. These include sliders, animation libraries, icon fonts and dozens of layout options. Your site loads a large share of that code even if it uses only a small part of it.
Unoptimised images
Photos uploaded directly from a camera or phone are often many times larger than they need to be. The browser downloads the full file, then scales it down to fit. Common problems include:
- Images far larger than the space they are shown in
- Older formats instead of WebP or AVIF
- Every image loading at once, including those far down the page
- A large hero image that delays the first view of the page
Slow hosting
A site can be well built and still be slow if the server is slow. Shared servers that host too many sites, an old PHP version and no server-side caching all add delay before the page starts to load. If most of your visitors are far from the server and the site has no content delivery network, they wait even longer.
Postponed updates
On a site with a builder and dozens of plugins, any update can break the layout. As a result, updates are postponed. Over time, the PHP version and the plugins go out of date, and the site becomes slower and less secure. Eventually, nobody wants to make changes to the site.
How to check your own site
You do not need to be a developer to check how your site performs.
Run Google’s PageSpeed Insights on mobile. Go to pagespeed.web.dev, enter your site’s address and look at the mobile result first. It simulates a mid-range phone on a slower connection. This is closer to how many of your visitors see the site than your office computer is. A score of 90 or more shows green. A score under 50 shows red.
Look at the Core Web Vitals. Google uses these as part of how it ranks pages:
- Largest Contentful Paint (LCP): how quickly the main content appears
- Interaction to Next Paint (INP): how quickly the page responds when someone taps or clicks
- Cumulative Layout Shift (CLS): how much the layout moves while the page loads
If your site gets enough traffic, PageSpeed also shows field data. This shows how the site performed for people who visited it using Chrome. It is the closest measure you have of what Google sees.
You can also run your site through our speed check.
Then look inside WordPress. Go to Tools, then Site Health. It shows your PHP version and lists known problems. While you are there, count your plugins and ask whether anyone can say what each one does.
Signs that small fixes will not be enough
- Updates you postpone because the last one broke something
- A page builder that makes small changes slow
- Thirty or more plugins, with nobody sure what half of them do
- A mobile PageSpeed score under 50
- A PHP version that is no longer supported
Quick fixes, and their limits
Some changes help without a rebuild. A caching layer, compressed images and removing plugins nobody uses can all improve speed. Sometimes that is all a site needs, and if so, we will tell you.
However, a lot of WordPress speed advice amounts to installing another plugin to fix problems caused by the others. Optimisation plugins that combine, defer and delay scripts can raise a score. They can also break menus, forms and checkouts in ways that only appear later. These plugins do not remove the causes. The builder, the large theme and the many plugins are still there, and so is the update problem.
What a lean rebuild changes
A lean rebuild keeps the parts that work. You still use WordPress, with the same admin area, login and URLs. The rebuild changes how the site is built and hosted:
- Theme: hand-coded for your site, so visitors download only the code each page needs
- Editing: native WordPress blocks instead of a page builder, so layouts stay consistent and edits are easy to make
- Plugins: a small number, each with a clear purpose. Where the theme can provide a feature, no plugin is used
- Images: served at the right size, in modern formats, and loaded only when they are needed
- Updates: automatic and monitored. If an update fails, the site rolls back and we investigate the cause
- Hosting: managed servers configured for WordPress, with caching, backups and SSL set up from the start
Content, SEO settings, forms and integrations move to the rebuilt site. Any page whose address has to change gets a redirect.
Our own site, capefrisco.com, scores 100 in all four PageSpeed categories on mobile. The site does not use WordPress. We built it on the same principles we now apply to WordPress, so each page loads only what it needs.
Why it’s worth doing
Speed affects how people find your site. Google uses page experience signals, including the Core Web Vitals, when it ranks pages. AI assistants increasingly read the web too. A page that loads quickly and uses simple, well-structured markup is easier for them to read.
A lean site is also less exposed to attacks. Fewer plugins mean fewer vulnerabilities and fewer emergency patches. Updates run automatically and roll back if they fail, so the site stays up to date.
A site built from standard WordPress blocks will also stay editable and supported for many years.
Where to start
Run your site through our speed check to see how it performs. If the scores are low, read how a lean WordPress rebuild works and what is included in our managed hosting. If you prefer to discuss it, send us your site’s address. We will tell you what we find, including when we think the site does not need changes.
Filed under Lean WordPress Rebuilds, Hosting & Managed Servers.