Speed5 min read
Why is my website slow on a phone?
Usually because it was built on a desktop, for a desktop: photos uploaded straight from the camera, a PDF menu, three fonts and a slideshow. On one bar of signal at Crooklets that is thirty seconds of white screen. The fixes are small images, a menu in the page, one font, and hosting that is close to your customers.
Written by Leonard Millard
Published Updated
What is the three second rule in web design?
It comes from a Google study of mobile sites and it is quoted so often that people have forgotten it was a measurement rather than a law.
of visits to a mobile site were abandoned when the page took longer than three seconds to load.
The figure is nearly ten years old and phones have improved since. So have people's expectations, which is the point: nobody has ever found that visitors got more patient.
Why is it fast on my laptop and slow on my phone?
Because the laptop is a best case and the phone is a real one. On the office computer the site is already in the cache, the screen is wide, and the wifi is three metres from the router. Your customer is in a car park with one bar, on a handset that is four years old, opening your site for the first time.
Most sites are built and signed off in the first condition and lived in by customers in the second. That gap is the whole problem, and it is why we check every build on an old phone on mobile data before it goes live.
of UK web traffic came from a phone in August 2026, with 49% from a desktop and 5% from a tablet. About half your visitors, then.
What actually makes a page heavy?
In nine cases out of ten it is one of these six, and they are all fixable without rebuilding anything.
- Photographs uploaded straight from a camera or a phone, several megabytes each, shrunk on screen but downloaded at full size.
- A menu, a tariff or a price list saved as a PDF, so a customer downloads a document and then pinches at it.
- Three or four different fonts, each one a separate download before any text appears.
- A slideshow on the front page that loads every slide whether anybody looks at it or not.
- A stack of plugins and tracking scripts added over the years, several doing the same job.
- Hosting on the other side of the world, so every request makes the round trip twice.
How do I test it myself?
About ten minutes, nothing to install and nothing to pay.
| What to do | Where | What good looks like |
|---|---|---|
| Open your own site on your phone, on mobile data with the shop wifi switched off | Your phone | The first screen is readable and the call or book button works within about three seconds |
| Put your web address through PageSpeed Insights | pagespeed.web.dev | The mobile assessment passes, and the largest thing on the screen appears in under 2.5 seconds |
| Open the Core Web Vitals report in Google Search Console | search.google.com/search-console | Your pages sit in the Good group for mobile, not Needs improvement |
Scroll the table sideways →
The 2.5 second mark is not ours. It is the threshold Google publishes for Largest Contentful Paint, one of the three Core Web Vitals it measures from real visits (Google, web.dev, 2026). Most sites do not clear all three.
of all websites measured passed all three Core Web Vitals on mobile in February 2026, up from 44% two years earlier.
Is it worth fixing?
The best evidence comes from very large retailers rather than from cafés, so treat it as a direction of travel rather than a promise about your own takings.
more retail conversions, and 10.1% more travel conversions, from a 0.1 second improvement in mobile speed. Measured across 37 large retail and travel brands, using 2019 data, not small businesses.
At the scale of a Bude business the honest version is simpler. Speed does not win you customers. It stops you losing the ones who were already on their way, which is the cheapest kind of growth there is.
What to fix first
- Re-save every photograph at about 2,000 pixels wide before uploading it. On most sites this is where nearly all the weight is.
- Take the menu or the price list out of the PDF and put it in the page as text, where Google and a phone can both read it. It is the first thing we do on a café, pub or restaurant site.
- Cut to one font, two weights.
- Replace the front-page slideshow with one image and one sentence.
- Measure again, on the same phone, in the same car park.
If that list reads like a job for somebody else, send us your web address for a free website check. We will open it on a real phone, tell you what is costing you the most, and roughly what it would cost to fix. Every price is on our pricing page, and we'll say honestly whether you need a rebuild or an afternoon's fix.
Quick questions about speed
Is my hosting what makes the site slow?
It can be, but on a small site it is rarely the main cause. Heavy photographs, a PDF menu, several fonts and a slideshow usually cost far more time than the server does. Fix those first. If the site is still slow after that, hosting that serves the pages from close to your visitors is the next thing to look at.
Does a slow website hurt my Google ranking?
Speed is one of the things Google measures, through its Core Web Vitals, but it is far from the only one. The bigger cost is people: a visitor who waits on a white screen goes back and taps the next result. A fast page is worth having for your customers before it is worth having for Google.
What does it cost to fix a slow site?
Sometimes very little: resizing the photographs and cutting the fonts can be a short job. Moving a PDF menu into a proper page is a new page, £145 to £245. If the site needs rebuilding, a Fast-Track Website is £1,195 to £1,795, or £25 a month with nothing upfront. The free website check tells you which it is.