EXECUTIVE SUMMARY
Most mobile problems come from a shortlist of causes: cramped tap targets, small text, slow loads, awkward forms and desktop-era layouts. This guide gives you ten fixes in priority order, the free tools to test each one, and an honest line on when patching stops making sense and a rebuild starts paying for itself.
KEY INSIGHTS
- Test on a real phone on mobile data; office wifi hides your real speed.
- Tap targets need roughly 44px of space; body text shouldn’t drop below 15 to 16px.
- Images are the number one cause of slow mobile pages.
- Forms lose more mobile visitors than any design element.
First, diagnose: the two tests that matter
Before fixing anything, get evidence. Open your site on a real phone, on mobile data, and try to do what a customer would: find your number, read your prices, submit the form. Then run your URL through Google PageSpeed Insights, which scores mobile performance and lists specific failures. If you want the theory behind why one adaptable site beats a separate mobile version, that’s covered in our guide to responsive web design; this article is the practice.
The 10 fixes, in priority order
1. Set the viewport correctly
One line of HTML tells phones how to scale your site. Without it, browsers render a shrunken desktop page. It’s the first thing to check and the fastest to fix.
2. Make tap targets thumb-sized
Links and buttons need around 44px of tappable space, with breathing room between them. Menu links designed for mouse pointers are the classic offender.
3. Get body text to at least 15 to 16px
If visitors pinch-zoom to read, you’ve lost half of them. Bump base font size and line height; readability is a conversion feature, not a style preference.
4. Compress and resize images
Multi-megabyte images are the top cause of slow mobile pages. Serve modern formats (WebP/AVIF), size images to their displayed dimensions and lazy-load anything below the fold. Speed work is unglamorous and pays better than any visual redesign, which is why it’s baked into every build we ship.
5. Simplify navigation
Collapse the menu, cap it at the pages people actually need, and keep the phone number or primary action visible at all times. On mobile, every extra choice costs you.
6. Shorten your forms
Every field loses people, and on a phone keyboard each one hurts double. Ask for the minimum, use the right keyboard types for email and phone fields, and never make someone type the same thing twice. Form design is pure UX design, and it’s where most mobile enquiries die.
7. Kill pop-ups and interstitials
Full-screen overlays that are hard to dismiss infuriate users, and Google explicitly penalises intrusive interstitials on mobile. If you must prompt, use a modest banner.
8. Fix horizontal overflow
Anything wider than the screen (tables, embeds, fixed-width elements) forces sideways scrolling and breaks the layout. Wide content should scroll within its own container, not drag the whole page.
9. Design for one-handed use
Key actions belong within thumb reach, which usually means bottom-of-screen patterns for critical buttons and generous spacing near screen edges.
10. Retest, then keep testing
Re-run PageSpeed Insights, check Search Console’s Core Web Vitals report, and repeat after every significant content change. Mobile-friendliness decays as sites grow; a maintenance plan exists to stop that quietly happening to you.
Your customers aren’t on your office wifi. Test on the phone in your pocket, on the data plan you pay for.
Patch or rebuild? The honest threshold
If your site fails two or three of these checks on sound foundations, targeted fixes are worthwhile. If it fails most of them, or was built desktop-only years ago, retrofitting costs more than rebuilding properly, and the result still creaks. That’s the point at which a website redesign becomes the economical option, especially since mobile experience now feeds directly into how Google ranks you. We’ll tell you which side of the line you’re on: send us your URL and we’ll diagnose it free.
Frequently asked questions
What’s a good mobile PageSpeed score?
Treat 90+ as the standard for a business site; it’s the score we build to and prove at handover. Below 50, speed is actively costing you visitors and rankings.
How long do these fixes take?
Viewport, text size and tap targets can be same-week jobs on a healthy site. Image and speed work varies with the platform. A full mobile-first rebuild typically runs 3 to 4 weeks for a brochure site.
Can you just fix my mobile issues without a full redesign?
Where the foundations are sound, yes, and we’ll quote exactly that. Where they’re not, we’ll show you why and quote a rebuild honestly. Either way, the quote is fixed and based on what yours actually needs.
