Checklist: Does Your Website Work on Mobile?

How to run the fifteen-minute test

Turn wifi off. Clear the browser tab so nothing is cached, or use a private tab. Search for your company on Google as a customer would and enter the site from the result. Then work through the sections below with the phone in one hand. Note each problem with a screenshot; that list becomes your brief.

Text size and contrast

• Body text is readable at arm's length without zooming. Around 16 pixels is a sensible minimum for body copy.
• Lines are not so long that you lose your place, and not so short that every sentence breaks after three words.
• Grey text on white, white text on photos and thin fonts are readable outdoors in daylight. Take the phone to a window and check.
• Headings wrap cleanly and do not break mid-word or push the first paragraph below the fold.
• Nothing scrolls sideways. If the page wobbles left and right, something is too wide.

Contrast is also a legal matter for some businesses. The accessibility requirements that apply to many consumer-facing services from 2025 include readable contrast, and our guide on brand colours that pass contrast shows how to check yours.

Tap targets and menus

• Buttons and links are large enough to hit with a thumb on the first try, with space between neighbouring links.
• The phone number is a tap-to-call link, and the address opens in a map app.
• The menu opens and closes easily, and you can reach every important page within two taps.
• The main action, such as Book, Call or Request a quote, is visible without hunting through the menu.
• Nothing important depends on hover, which does not exist on a touch screen.

Forms on a phone keyboard

Forms are where mobile visitors give up most often, because every field is work with a thumb. Fill in your own contact or booking form completely.

Our guide on contact forms that get filled in goes deeper into field order and wording.

Speed on a mobile connection

On office wifi and a new phone, almost every site feels fast. Your customers use older phones on a train or in a car park. Count, honestly, how long it takes before you can read the first screen and before you can tap the main button. If either feels slow, it is slow.

• The first screen appears within a couple of seconds on mobile data.
• Images do not jump the text around as they load.
• Buttons respond immediately when tapped, not after a delay.
• Run Google PageSpeed Insights on the mobile tab for a second opinion and note the Core Web Vitals.

The usual causes are oversized images, too many scripts and cheap hosting; why your website is slow walks through them.

Pop-ups and sticky elements

• The cookie banner can be accepted or rejected with one tap each and does not cover the whole screen.
• Newsletter or offer pop-ups do not appear before the visitor has read anything, and close with an obvious button.
• Chat widgets do not cover the main button or the bottom of the form.
• Sticky headers and bars together take up a small slice of the screen, not a third of it.

Decision rule: if you fail items on the path to contact or purchase, fix those this month; they cost enquiries every day. If you only fail cosmetic items, schedule them with your next update. When you do not need help: most text, menu and form fixes can be done in your website builder by whoever edits the site. Bring in a developer when the problems are speed, layout that breaks on some phones, or a theme you cannot change. Our performance and SEO service covers those, and you can book a short call to go through your screenshots.

Frequently asked questions