What a visitor on a phone sees
The first screen of each version, loaded on the same phone-sized browser.
Self-initiated demo by Flow Lab. Tarnside Roofing is invented.
This is a worked example on an invented business: the “before” site was built with problems that are common on small-business sites, then fixed and measured. It looked passable on a desktop. On a phone it was slow to load, the text was too small to read, the phone number was a line of text about 6 px high with no call button, and the contact form lost every enquiry. Here is the fix, measured before and after the same way.
The first screen of each version, loaded on the same phone-sized browser.
Measured on a phone-sized browser over a slow mobile connection, with the processor slowed four times, the way Lighthouse imitates a mid-range phone. Each version was loaded three times with an empty cache; the table shows the middle result. Both ran on a local test server, so real hosting would add some time to both.
Nothing was redesigned: same sections, same pictures, same font. The text was tightened a little, grey text made darker, and the buttons given one brand colour. Each fix is small on its own.
Both versions are served from one local server and opened in headless Chrome set to an iPhone screen size (390 × 844). The connection is slowed to 150 ms latency and 1.6 Mbit/s, and the processor to a quarter of its speed, so the numbers are closer to a phone on weak 4G than to a laptop on Wi-Fi. “Time until the main picture appears” is the browser’s Largest Contentful Paint. The form was sent once to a test endpoint on the same server, which recorded the enquiry; on a real site it would go to the owner’s inbox. The checks in the last row come from the same script I run on a real site before I write to its owner. Tarnside Roofing is invented; the pictures were drawn in code, and the phone number is from the range Ofcom keeps for fiction.
A list of what is wrong on your site, each item with proof, like the table above. You decide what to fix.
Your text, pictures and look stay. Whether it runs on WordPress, Shopify or plain HTML, the fixes go into what you already have.
The same measurements after the work, so you can see what changed rather than take it on trust.
Each month: the form still delivers, the site still loads fast, and nothing new has broken.
Want the same check on your own site? Send me its address through the contacts on the Flow Lab page.