Why is my website slow, and is it costing me customers?

What a slow page costs your visitors

On fibre at the office, almost any website feels fine. Your customers are mostly not on fibre. They are on a phone, in a taxi or a parking lot, on a signal that comes and goes, and every megabyte comes out of a data bundle they paid for.

The typical mobile web page now weighs about 2.3 MB, and the heaviest tenth weigh 7.7 MB or more, according to the HTTP Archive's 2024 report. Pick a page below to see what that means on a weak signal, on fibre, and in rands.

A few cents a visit sounds small. But on a weak signal the heavy page takes over half a minute just to arrive, and most people won't wait that long for a plumber or a guest house. When Vodafone made its main content load 31% faster in a test, it saw 8% more sales (web.dev case study, 2021). Speed is not a nice-to-have.

What usually makes a small-business site slow

On a typical mobile homepage, images alone are about 900 KB and code (JavaScript) about 560 KB. That is where most of the weight hides. The usual culprits:

Huge images

A photo straight off a phone is often several megabytes. Shown on a small screen, it only needs to be a fraction of that.

Too many plugins and scripts

Every add-on brings its own code, and the phone has to download and run all of it before the page settles.

Chat widgets and trackers

Live chat bubbles, pop-ups, heatmaps and several analytics tags all load on every page, for every visitor.

Autoplay video and big sliders

A background video or a five-photo slider at the top of the page is often the heaviest thing on the site.

Page builders

Drag-and-drop builders are easy to use, but many add a lot of extra code to every page to make that possible.

Cheap, crowded hosting

On the cheapest shared plans, your site shares a server with many others. When they are busy, your site waits.

No caching

Caching means the server keeps a ready-made copy of each page. Without it, the page is rebuilt from scratch on every visit.

Test your site in one minute

Google's PageSpeed Insights is free and needs no sign-up. It loads your page on a simulated mid-range phone and tells you what is slow.

1. Go to pagespeed.web.dev on your computer or phone.
2. Type in your website address and tap Analyze.
3. Look at the Mobile tab first. That is the version most of your customers see.
4. Read the three numbers below, then the score. A score of 90 to 100 is good, 50 to 89 needs work, under 50 is poor.

Above the score, if your site gets enough visitors, you'll see how real Chrome users experienced it over the last 28 days. Those are the Core Web Vitals, Google's three speed checks. In plain words:

Largest Contentful Paint

How long until the main thing on the page (usually the big photo or heading) shows. Good is 2.5 seconds or less.

Cumulative Layout Shift

Whether things jump around while the page loads, so people tap the wrong button. Good is 0.1 or less.

Interaction to Next Paint

How quickly the page reacts when someone taps a button or opens a menu. Good is 0.2 seconds or less.

Scroll down to “Diagnostics” and it lists the biggest problems, with the heaviest files named. You don't need to understand every line. The top two or three tell you where to start.

The fixes that matter most, in order

Start at the top. The first two are cheap and often fix most of the problem.

1. Shrink and resize your images. Biggest win, least effort. Save them at the size they are shown, in a modern format like WebP.
2. Remove what you do not use: old plugins, a chat widget nobody answers, tracking tags from a campaign that ended.
3. Stop autoplay video. Show a still image and load the video, or the Google map, only when someone taps it.
4. Turn on caching, and a CDN if your host offers one. A CDN keeps copies of your site on servers closer to your visitors.
5. Move to better hosting if the server itself is slow. PageSpeed Insights flags this as a slow "server response time".
6. Rebuild the site if it sits on a heavy theme or page builder. Most effort, but sometimes the only way past the 50s.

Every site we build has to score 90 or more for mobile performance before we hand it over. That is our launch guarantee. You can see the measured mobile speed of live client sites on our portfolio.

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