How fast should your site load on a phone

Almost every visitor to a local business website is on a phone, and often not a new one, on a signal that comes and goes. That is the real test, not how the site feels on the machine it was built on.

The numbers, briefly

Google publishes a page experience threshold called Largest Contentful Paint: the main content of the page should appear within 2.5 seconds. Under a second feels instant. Past about three seconds people start leaving, and the ones who stay have already formed an opinion about how organised you are.

Aim for the main headline and the phone number visible in under a second on 4G. It is achievable for a small business site. It is very hard for a heavy one.

What actually makes small sites slow

• Photographs straight from a phone or camera, three or four megabytes each, shown at a fraction of their size.
• A homepage slider, which loads several of those photographs before anything appears.
• A page builder plugin that ships large amounts of CSS and JavaScript for a layout you could do in a few lines.
• Half a dozen tracking scripts, chat widgets and cookie banners, each fetched from somewhere else.
• Cheap shared hosting that takes a second to respond before the page even starts loading.

Most slow websites are not badly designed. They are just carrying things nobody looks at.

How to test it properly

Open your own site on your phone, on mobile data, standing outside. Count. That is the honest test, and it usually settles the argument faster than any tool.

For numbers, PageSpeed Insights gives you a mobile score and, more usefully, the LCP figure and a list of what is holding it back. Ignore the score out of a hundred and look at the timings. A site can score well and still feel slow if the important part appears last.

What I do instead

I write the pages by hand, so a page ships the markup and styles it actually uses and nothing else. Images get resized to the size they are displayed at and converted to WebP, which usually takes a three megabyte photograph down to under two hundred kilobytes with no visible difference.

Fonts are limited to one or two weights and loaded so text appears immediately rather than after the font arrives. Anything that is not needed for the first screen loads later. The site sits on Cloudflare, which serves it from a location near the visitor.

The aim is a first load of around a second on a phone, and repeat visits that feel instant. Not because of a trick, but because there is very little to download.

If you have a slow site now

You do not necessarily need a rebuild. In order of effect: resize and compress every image, remove plugins and widgets you do not use, take the slider off the homepage, and check what your hosting response time actually is. That often halves the load time in an afternoon.

If the theme itself is the problem, and it often is, then a rebuild is cheaper than fighting it for another two years.