Why your website is slow on a phone, and what to fix first

Your website probably feels fine on your office Wi-Fi. Your customers aren't on your office Wi-Fi. They're on one bar of signal in a parking lot, on hotel Wi-Fi in July, or at a venue walkthrough in a building with thick walls. That's where slow sites lose people, and most owners never see it.

When we rebuilt Pierpoint Events' site, the old home page hid behind a black loading screen for about 40 seconds on a weak signal. The new one is readable in about 2. Here's what usually causes the problem, and what to fix first.

Test it the honest way

• Use your own phone, off Wi-Fi, somewhere with weak signal. Count how long until you can read the page.
• Run Google's PageSpeed Insights on your home page and look at the mobile score, not the desktop one.
• Check the page size. Several megabytes for a home page is a lot of data to push down one bar of signal.

The usual culprits

• Oversized photos. A photo straight off a camera can be several megabytes, sent to a phone that shows it a few inches wide. This is the most common problem by far.
• Page builders and heavy themes. Drag-and-drop builders load code for every feature they might ever need, on every page.
• Too many third-party scripts. Chat widgets, trackers, review badges, pop-ups and embedded feeds each add their own files and delays.
• Loading screens and sliders. A spinner or a slideshow in front of your content means nobody sees anything until it all arrives.
• Lots of fonts. Every font weight is another file to download before text looks right.
• Plugins piled up over the years, each adding a little more to every page.

What to fix first

1. Shrink the photosResize each image to the size it's actually shown, use a modern format, and send smaller versions to smaller screens. This alone can cut a page's weight dramatically.
2. Kill the loading screenShow the headline and the call button first. Let photos fill in after.
3. Cut the scriptsList every third-party tool on the page and remove anything nobody uses. Load the rest after the page appears.
4. Trim fontsTwo weights of one family is plenty for most sites.
5. Stop the layout jumpingGive images and embeds their size ahead of time, so the page doesn't shift as they load and someone taps the wrong thing.

What Pierpoint's rebuild changed

Pierpoint Events' home page went from 7.3 MB and 133 files to about 0.67 MB and 34 files. Real event photos are sent at the size each screen needs, the headline and the date check paint first, and nothing jumps while the rest loads. Google's mobile performance score went from 50 to 85, with accessibility, best practices and search all at 100. See the full case study.

Sometimes a slow site can be repaired. Sometimes the builder underneath is the problem, and a rebuild is the honest fix. Either way, the photos are almost always the place to start.

Why it matters beyond patience

Google measures how real visitors experience your pages (it calls these Core Web Vitals: how fast the main content appears, how quickly the page responds to a tap, and how much it jumps around) and uses page experience as one of its signals. More importantly, a customer who gives up waiting calls someone else.