Mobile SEO: What to Check When Google Only Looks at Your Phone Version

There's a curious asymmetry in how websites get built and used: they're designed and approved on 27-inch screens, and visited on 6-inch ones. The majority of almost any business's traffic arrives from phones — and Google knows it so well that for years it has applied mobile-first indexing: it evaluates and ranks your site by looking exclusively at its mobile version.

The practical consequence is brutal in its simplicity: whatever isn't right on your mobile version, isn't right — full stop. This guide is the checklist: what to look at, in what order, and the mistakes that cost the most positions and the most customers.

Mobile-first: your website IS the mobile version

Mobile-first indexing means Google's crawler visits your site presenting itself as a phone, and what it sees there is what gets indexed: that content, those links, that speed. The desktop version is no longer "the main one with a mobile adaptation" — it's the other way round. So the first habit to change is the review habit: every new page gets approved by looking at it on a real phone, not by shrinking the office browser window.

The quick review: ten minutes with your phone

• No zooming, no sideways scrolling: if you have to pinch the screen to read or something sticks out the side, there's a foundational problem.
• Text readable without effort: a real minimum of 16 pixels for body copy; grey blocks of tiny text push people out.
• Buttons and links tappable with a thumb: targets of at least 44–48 pixels with air between them — two links stuck together produce mis-taps and rage.
• The menu works with fingers: dropdowns that open and close properly, no submenus demanding surgeon-level aim.
• Tappable phone and WhatsApp: a number that doesn't launch the call when touched is a lost conversion.
• Images fit and load: no giant photos shoving the content around, no galleries freezing the phone.

Content parity: what you hide on mobile doesn't exist

Speed: the mobile network doesn't forgive

The speed that matters is a phone's on a data connection, not your office's on fibre. The metrics — and how to improve them — are in the Core Web Vitals guide; for mobile diagnosis, two habits: measure in PageSpeed Insights looking at the mobile tab (the demanding one), and try your site on mobile data from a normal phone — not the latest model — at least once a month. What takes 2 seconds on your desktop can take 9 on your customer's phone.

Popups: on mobile, Google punishes them explicitly

Notices that cover the screen on arrival — intrusive interstitials — carry a specific mobile penalty: Google demotes pages where the content isn't immediately accessible. On a 6-inch screen, any popup is full-screen. The alternatives that destroy neither the experience nor the ranking — discreet banners, delayed notices, accepted formats — are in popups without ruining the experience.

Forms and conversion: where mobile wins or loses the money

The form is the most profitable fix of all: half of abandoned mobile submissions are explained by extra fields and wrong keyboards. The full detail is in forms that convert — and all of this sits inside the broader SEO guide.