Which devices should you test your website on?

Key takeaways

Which devices to test a website on is a smaller question than it sounds. You do not need a device lab. Five devices, chosen to cover both phone platforms, a small screen, a slower processor and a laptop, catch nearly every problem a UK visitor will meet. The best guide to the exact set is your own analytics.

• 53% of UK phone web traffic is on Android and 47% on iPhone (StatCounter, September 2026).
• Test on at least one iPhone and one Android phone, every time.
• Include a small screen and a mid-range or older handset.
• Emulators show layout. Only real devices show speed, touch and keyboards.

Why does device choice matter?

Device choice matters because websites behave differently across platforms, screen sizes and processing power, and the people approving a site usually own the newest and fastest phones. A layout that is flawless on this year's flagship can be cramped on a smaller model and sluggish on a three-year-old budget handset.

The UK is unusually evenly split. StatCounter's figures for September 2026 put Android at about 53% of mobile web traffic and iOS at about 47%. Testing on one platform alone leaves roughly half your mobile visitors unchecked.

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Which five devices cover most UK visitors?

A practical set is five devices: two iPhones, two Android phones and a laptop. Between them they cover both browser engines, the narrowest common screen and a realistic range of speed. A tablet is a useful sixth if your analytics shows meaningful tablet traffic.

• A recent iPhone with Safari: the most common single browser on UK phones.
• A small or older iPhone: narrower screen and an older version of iOS.
• A mid-range Android phone with Chrome: closer to the typical visitor than a flagship.
• A Samsung phone with Samsung Internet: a distinct browser many owners use by default.
• A laptop with Chrome and one other browser, such as Safari or Edge.

• Website not working on iPhone? The usual Safari causes

How do you choose from your own data?

Open Google Analytics 4, go to Reports, Tech, Tech details, and view by device category, operating system, browser and screen resolution. The report shows what your visitors actually use. If 60% are on iPhones, weight your testing that way. If a particular screen width is common, make sure it is in your set.

The GOV.UK Service Manual gives the same advice for public services: test in the browsers and on the devices your users have, and review the list regularly as usage changes. A list that was right three years ago will be testing phones few people still carry.

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What do emulators miss?

Emulators and browser previews show how the layout looks at a given screen size. They do not reproduce the things that most affect a real visitor. Chrome's documentation describes device mode as a first-order approximation of how a page looks and feels on a mobile device.

• Real processor speed: scripts that run instantly on a laptop can stall a mid-range phone.
• Touch: whether a thumb can hit a target, and what happens on a mis-tap.
• The on-screen keyboard, which covers half the screen during forms.
• Browser differences: Safari and Samsung Internet do not behave exactly like Chrome.
• Mobile data, signal drops and the browser's own toolbars.
• Features such as tap-to-call, maps links, wallets and the camera.

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What should you test on each device?

Test tasks, not pages. On each device, do the four or five things a customer does, start to finish, and note anything that slows or stops you. A fixed script makes results comparable between devices and between test rounds.

• Arrive from a Google search and read the first screen.
• Open the menu, find a service and find a price.
• Tap to call, open WhatsApp and get directions.
• Complete and submit the enquiry or booking form.
• Rotate the phone, scroll a long page and dismiss any banner.
• Repeat the form with larger system text switched on.

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How much testing is enough?

Enough is every template on every device in your set before a launch, and a short check of the main journey after any change to templates, plugins or tracking scripts. For a typical small business site that is an hour or two, not a project.

The trade-off is cost against coverage. Cloud testing services offer hundreds of real devices for a monthly fee and suit agencies and larger sites. For a small business, borrowed phones from colleagues and family cover the same ground for nothing. What matters is that the test happens on hardware, by a person, before customers find the problem.

• Website launch checklist

What does this look like in practice?

A pattern we see after launches: the site was tested thoroughly on the designer's large iPhone and on a laptop. A week later a customer mentions that the booking form cannot be submitted. On a smaller Android phone, the submit button sits beneath a chat widget and cannot be tapped.

No tool reported it, because nothing was technically broken. One pass on a second phone would have found it in a minute. Global Bridge Labs (GBL) signs off sites on a fixed set of iPhone and Android devices, including an older mid-range handset, for exactly this reason.

• See client work
• Website Design & Development for UK businesses
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Device testing checklist

• Check your analytics for the devices and browsers visitors use.
• Assemble two iPhones, two Android phones and a laptop.
• Write a short task script covering your main journeys.
• Run it on every device before launch.
• Re-run the main journey after any template or plugin change.
• Test on mobile data, not office Wi-Fi.
• Review the device list once a year.

Next step

Borrow the oldest phone in the office and the one that is not the same make as yours. Try to enquire through your site on both. You will learn more in ten minutes than from any report.