A mobile friendly test checks whether your site works properly on a phone: readable text, tappable buttons, content that fits the screen, and nothing blocking the way. Since Google’s mobile-first indexing, the mobile version of your page is the one Google primarily uses to rank you — so a desktop-only site now ranks badly everywhere.
A few years ago I ran this test on a local restaurant’s website and expected a clean pass. On a desktop it was lovely: big food photos, a clear menu, a reservation button right at the top. On a phone it was a different story. The menu opened as a PDF that pinched and zoomed awkwardly, the phone number was an image rather than a tappable link, and the reservation button sat so close to the screen’s edge that thumbs kept missing it. The owner had no idea — he had only ever opened his own site on his office computer. His customers were finding him on their phones, struggling, and quietly going elsewhere. That gap is exactly what a mobile friendly test exists to close.
What is a mobile friendly test?
A mobile friendly test is a structured check of how your site behaves on a small screen. It answers one question: can a visitor on a phone read, navigate, and act on your page without frustration? The classic checks are simple:
– Text size. Can visitors read your body text without pinching to zoom? Body text below about 16 pixels is a common failure.
– Tap targets. Are links and buttons big enough and spaced far enough apart for a finger? Google recommends tap targets at least 48 pixels tall with adequate spacing.
– Content width. Does everything fit the screen, or does the page scroll sideways? Horizontal scrolling on a phone is a hard fail.
– Viewport configuration. Does the page declare a viewport meta tag so the browser knows how to scale it? Without one, phones render the desktop layout shrunk to fit, which is unreadable.
– Intrusive elements. Do pop-ups, banners, or sticky bars cover the content on a small screen?
Google’s old standalone Mobile-Friendly Test tool is now folded into Search Console and PageSpeed Insights, but the checks are unchanged — and you can run most of them yourself in five minutes.
Why does mobile-first indexing make this test matter?
Mobile-first indexing means Google’s crawler looks at the mobile version of your page first when deciding what it is about and where it should rank. It is not a separate mobile ranking or a bonus — it is the main ranking. If content exists only on your desktop version, Google may simply not see it. Content hidden behind tabs or accordions still counts, but only if it is present in the mobile page’s code.
This flips the old way of thinking: for years, people designed for desktop and checked mobile afterwards. Under mobile-first indexing, the phone version is the real version. A mobile friendly test is therefore not a cosmetic check — it is a check of the exact page Google is judging.
How do you run a mobile friendly test yourself?
You do not need a paid tool. Here is the pass I run on every site, in order.
Step 1: Open your site on a real phone. Borrow one if you have to. Scroll the whole homepage slowly, noting anything you must zoom to read, swipe sideways to see, or tap twice to hit. Real thumbs catch things emulators miss.
Step 2: Check the viewport and text size in DevTools. In Chrome, press F12, toggle device mode, and set the width to 375 pixels — the most common phone width. If the page renders as a tiny shrunken desktop layout, the viewport meta tag is missing or wrong. Look for this line in your page’s head: <meta name="viewport" content="width=device-width, initial-scale=1">. If it is absent, that single line is your highest-value fix.
Step 3: Run PageSpeed Insights and read the mobile report. Enter your URL, switch to the mobile tab, and ignore the score for a moment. The diagnostics — “tap targets are not sized appropriately,” “content is not sized correctly for the viewport,” “text is too small to read” — name the exact elements at fault.
Step 4: Check Search Console’s mobile usability data. Its Mobile Usability report (under Experience) lists real issues Google found across your pages. Fix the ones flagged on your most-visited pages first — that is where a fix moves the most traffic.
Step 5: Test the actions, not just the look. On a phone, complete the thing visitors come to do: submit the form, tap the phone number, find the opening hours. A page can look mobile-friendly and still fail at the moment that matters — a form field hidden behind a sticky banner, or a phone number that is a picture instead of a link.
What does a mini mobile friendly test look like in practice?
A quick test I ran on a small brochure site before its relaunch shows how it works. At 375 pixels wide, the homepage looked fine — until I started tapping. The navigation links were 32 pixels tall and packed together, so my thumb kept hitting the wrong page. The hero image had no responsive sizing, forcing sideways scrolling. And the submit button sat underneath a sticky cookie banner, unreachable until it was dismissed.
Three fixes, none of them a redesign: wider mobile menu spacing, responsive sizes for the hero image, and a compact cookie bar that no longer overlapped the form. A second pass came back clean — readable text, tappable links, no sideways scroll, and a form a thumb could submit. To see your own site at phone, tablet, and desktop widths side by side before you start fixing, try it on your own site with our responsive preview tool — it makes the before-and-after visible in seconds.
What are the most common mobile friendly test failures?
The same failures keep appearing on small sites:
– Text too small to read. The number-one finding — body text set for desktop becomes unreadable on a phone.
– Clickable elements too close together. Spread navigation links and footer links out, and make them at least 44–48 pixels tall.
– Content wider than the screen. Usually one culprit: a fixed-width image, a long URL, or a table. Find it with DevTools and resize it.
– A viewport that is not set. The classic cause of the “tiny desktop site” look. One meta tag fixes it.
– Pop-ups covering the content. A full-screen newsletter modal on a phone is a wall, not marketing. Keep mobile prompts small and dismissible.
– Desktop-only content. A phone number shown as an image or a menu delivered as a PDF does not exist for phone visitors.
How often should you run a mobile friendly test?
Run it before every launch and redesign, and again whenever you change a theme or add a layout-affecting plugin. Between those events, a quick quarterly check is enough for a stable site. The test takes minutes; the rankings it protects take months to build.
FAQ
What is a mobile friendly test?
A mobile friendly test checks whether your website works well on a phone: readable text without zooming, tap targets big enough for fingers, content that fits the screen, and nothing blocking the page. Under mobile-first indexing, the mobile version is the version Google primarily uses for ranking.
Is Google’s Mobile-Friendly Test tool still available?
Google retired the standalone tool and folded its checks into PageSpeed Insights and Search Console’s Mobile Usability report. You can also run the core checks yourself: open your site at 375 pixels wide in responsive mode and look for small text, cramped tap targets, and sideways scrolling.
What is mobile-first indexing?
Mobile-first indexing means Google predominantly uses the mobile version of a page for indexing and ranking. If that version is missing content or broken, that is what Google judges — even for desktop visitors.
How do I fix a site that fails a mobile friendly test?
Start with the highest-impact fixes: add the viewport meta tag if missing, raise body text to at least 16 pixels, space tap targets to 44–48 pixels tall, and fix any element wider than the screen. Then re-test at 375 pixels wide.