Why is my WordPress slow, and how do I make it faster?

A slow WordPress site almost always has one of six causes: an outdated PHP version, no object caching, images that are too heavy, too many plugins, a heavy theme or page builder, or hosting that does not fit the site. First measure which one it is, then tackle that one cause. Half of them you fix yourself; the other half comes as standard with good hosting.

Below are the six causes, each with what you can do yourself and what is already included in the plan at WWW4. At the bottom you can read how to measure before you intervene, because optimising blindly costs time and delivers little.

Six causes of a slow WordPress site

In order of how often we see them. The first two you fix without changing a single line of code.

1. An outdated PHP version

Every new PHP version processes the same WordPress code faster than the previous one, and old versions no longer receive security updates. Yet many sites still run on a version from years ago, simply because nobody ever switched them.

What you do yourself

Check in your control panel which PHP version your site uses. Check whether your theme and plugins support a more recent version, make a backup and switch. If something breaks, switch back and you know which plugin is due for replacement.

What WWW4 delivers

You choose the PHP version per site yourself, from PHP 8.5 and 8.4 to older versions for those who cannot switch yet. Switching over and back is up to you, at any time.

2. No object caching

WordPress requests the same data from the database on every page view: options, menus, widgets, metadata. On a busy site or a webshop with many products, the database becomes the bottleneck as a result.

What you do yourself

Check whether your site uses an object cache; in the WordPress dashboard, under Site Health, you can see whether a persistent object cache is active. If not, that is the first question for your hosting provider.

What WWW4 delivers

Redis object caching comes with every hosting plan. The database's answers stay in memory, so the same query is not asked over and over.

3. Images that are too heavy or too many

The most common cause we see on business sites. Photos straight from the camera, thousands of pixels wide, on a page that shows them at 800 pixels. The server is not slow then; the page is simply too heavy.

What you do yourself

Resize images before uploading to the size at which they are displayed. Use modern file formats, let images below the fold load only when the visitor scrolls, and clean up the media library.

What WWW4 delivers

The Jaan Performance Engine, our own WordPress plugin, comes free with your hosting and takes care of image optimisation and caching of your pages, without a separate license.

4. Too many plugins

It is not the number that counts, but what they do. One badly written plugin that queries an external service on every page weighs more than ten tidy ones. But the more plugins, the greater the chance that one of those is among them.

What you do yourself

Deactivate plugins one by one on a test copy and measure the difference. Remove what you no longer use, and replace plugins that do one small thing with a line in your theme or with a lighter alternative.

What WWW4 delivers

We can see in the server logs which requests take long. If you suspect a plugin is the culprit, we look along with you and tell you which one.

5. A heavy theme or page builder

Page builders and multi-purpose themes load scripts and styles for every feature they know, including the features your site does not use. That costs computing on the server on every page view and load time in the browser.

What you do yourself

Check whether your page builder lets you disable unused components. If you are building a new site, weigh up whether you really need the page builder; the standard WordPress block editor has matured a great deal.

What WWW4 delivers

A heavy page builder needs more working memory per request. Our plans differ in PHP memory limit, from 128 to 512 MB, so you can pick a plan that suits your theme.

6. Hosting that does not fit the site

A webshop with thousands of products on the smallest plan, or a site that hits its memory limit at peak times. Then the site is not the problem but the environment, and no plugin will help.

What you do yourself

Look at the pattern: is the site always slow, or mainly at busy moments? Only at peak times points to too few resources. Always slow points to one of the five causes above.

What WWW4 delivers

SSD storage with every plan, and a clear growth path: from the smallest plan to a larger one, and when shared hosting is no longer enough, to a managed VPS with its own resources.

How much faster your site gets from each of these measures depends entirely on your theme, your plugins and your content. We do not put a percentage on that. What we can say: the things on our side are included in the plan as standard, you pay nothing extra for them.

Measure first, then intervene

Anyone who starts optimising without measuring loses time on the wrong thing. So first measure how your site loads now, paying attention to the Core Web Vitals: the three metrics Google uses to judge how quickly a page becomes visible, how quickly it responds and whether the layout shifts while loading. You do not need to buy a tool for that; Google's own measurements are free and also show what real visitors experience.

Look at the distinction between server time and load time in the browser. If it takes long before the first byte arrives, the problem is on the server: PHP version, database, memory or hosting. If the first byte arrives quickly but the page then loads slowly, it is in what the page drags along: images, scripts, theme. That one distinction decides which half of the list above is relevant to you.

Measure again after every change, and change one thing at a time. Otherwise you will not know afterwards what helped and what did not.

What WWW4 delivers as standard

The causes on the server side are not yours to solve with us. This comes with every hosting plan.

Choose the PHP version per site yourself, with PHP 8.5 and 8.4 available
Redis object caching for the database
Jaan Performance Engine for caching and images, included free
SSD web space with every plan
PHP memory limit from 128 to 512 MB, depending on the plan
Growth path to a managed VPS when shared hosting is no longer enough
About the Jaan Performance Engine When a VPS?

Further reading

Want to get started yourself? The knowledge base articles below take you through it step by step.

Jaan Performance Engine WordPress hosting
My website is suddenly slow: where do I start?
Cleaning up the WordPress database
Raising the PHP memory limit

Frequently asked questions about a slow WordPress site

Almost always because of one of six causes: an outdated PHP version, no object caching, images that are too heavy, too many or badly written plugins, a heavy theme or page builder, or hosting that does not fit the site. First measure whether the delay is on the server or in the browser; that decides which causes are relevant to you.
Look at the time to first byte. If it takes long before the server starts answering, it is on the server side: PHP version, database, memory or too few resources. If the answer comes quickly but the page then loads slowly, it is in the page itself: images, scripts, theme. A site that is only slow at peak times is usually short of resources.
WordPress requests the same data from the database on every page view. Object caching keeps those answers in memory, so the database does not do the same work every time. On a quiet business site you hardly notice it; on a busy site or a webshop with many products it makes a noticeable difference. At WWW4 Redis object caching comes with every plan.
Yes. Every new PHP version processes the same code faster than the previous one, and old versions no longer receive security updates. Do check in advance that your theme and plugins support the new version, and make a backup. At WWW4 you choose the version per site yourself and can switch back if something breaks.
That depends entirely on your theme, your plugins and your content, so we do not put a percentage on it. A site with a heavy page builder and thirty plugins has a very different profile from a simple business site. What is certain: PHP choice, Redis object caching, SSD and the Jaan Performance Engine are included in the plan as standard.
Our own WordPress plugin for caching and image optimisation, included free with every WWW4 hosting plan. You do not need a separate license for it and no third-party plugin to maintain. The details are on the plugin's own page.
There is no magic number. One plugin that queries an external service on every page weighs more than ten tidy plugins. So do not look at the number but at what each plugin does, remove what you do not use, and test on a copy of the site which plugin makes the difference.
When the site becomes slow mainly at busy moments while theme and plugins are in order, when you structurally hit the memory limit, or when you need your own server software or shell access. Then a managed VPS is the next step: your own resources, without neighbours affecting your performance. For most WordPress sites, shared hosting is more than enough.
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