Why is my website slow on mobile?

Why phones feel the difference most

Phones often work on weaker connections than a desktop on broadband, and they have less processing power to run heavy pages. Every unnecessary photo, script and font has to be downloaded and processed before the page is usable. On a desktop you might not notice. On a phone in a car park with two bars of signal, it can be the difference between a customer calling you and a customer pressing back.

How to check your site properly

1. Use your phone, not your computer. Turn off Wi-Fi and load your site on mobile data.
2. Open it in a private tab so your phone is not using a saved copy.
3. Time how long it takes before you can read the text and tap a button, not just until something appears.
4. Use a speed testing tool. Google's PageSpeed Insights is free and gives a mobile report with specific suggestions.
5. Test more than the home page. Service pages and galleries are often slower.

The usual causes

Oversized photos

This is the most common problem on small business sites. A photo straight from a modern phone or camera is far larger than any screen needs. If it is uploaded as it is, every visitor downloads the full file. Images should be resized to the size they are shown at and saved in an efficient format.

Too many plugins and add-ons

On systems like WordPress, each plugin can add its own code to every page. Sliders, social feeds, chat widgets, pop-ups and page builders all add weight. Over the years, sites collect plugins nobody remembers installing.

Heavy themes and page builders

Multi-purpose themes are built to do everything, which means they load code for features you do not use. Visual page builders can generate a lot of extra code behind the scenes.

Tracking and third-party scripts

Analytics, advertising pixels, heatmaps and embedded social feeds all load code from other companies' servers. Each one adds delay, and some also need cookie consent. Our guide to cookies and UK GDPR explains why.

Slow or overloaded hosting

Very cheap shared hosting can be slow to respond, especially when the server is busy. If pages take a long time before anything at all appears, hosting is a likely suspect.

Pages built on every visit

Many systems assemble each page from a database every time someone visits. Static pages, which are prepared in advance, can be sent straight away and are much quicker.

Custom fonts and autoplay video

Several font families in multiple weights, or a large background video on the home page, can slow the first view considerably on a phone.

Fixes you can make today

• Resize and compress your largest photos before uploading them again.
• Remove plugins and widgets you do not genuinely use.
• Remove tracking tools you never look at.
• Replace autoplay background videos with a good photo.
• Limit yourself to one or two fonts.
• Embed videos so they only load when someone taps play, where your system allows it.

When it is time to start again

If you have done the quick fixes and the site is still slow, the problem usually lies in the theme, the system or the hosting. You can spend a lot of time and money tuning an old site, or replace it with one built to be fast from the start. Our article on signs your website is outdated can help you decide.

Speed is not the only mobile check

A fast site still needs to be easy to use on a small screen: readable text, buttons big enough for a thumb, a tap-to-call phone number and a short contact form. The tradesperson website checklist covers these.

Fast by design with Site Shifter

Site Shifter publishes static, fast pages and resizes your images automatically, so you do not need to think about file sizes. There is no visitor tracking, which means no tracking scripts slowing things down and no cookie banner covering the screen. You can still embed Google Maps and videos where they help. See all the features, or if you are on Squarespace, read about switching from Squarespace.

Frequently asked