Mobile-Friendly Test
Checks the viewport declaration, zoom blocking, fixed-width elements and tiny font sizes straight from the HTML. Google indexes the mobile version, so these checks touch rankings directly.
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- Open on the Pro plan100 runs a day
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What does this tool look at?
Everything that decides whether Google can crawl and index your page: tags, redirects, robots, sitemaps and server responses.
- Whether the viewport meta tag is correct
- Whether zoom is blocked (an accessibility fault)
- Elements with a fixed pixel width
- Font sizes declared below 12 pixels
What this tool measures
Google crawls your site with a phone browser and indexes the mobile version it sees. If a page looks perfect on desktop but demands horizontal scrolling or has unreadable text on a phone, that broken version is the one Google is judging.
The tool downloads the page HTML and looks for five structural signs that break the mobile experience: a missing or wrong viewport declaration, blocked zoom, fixed-width elements wider than 480 pixels, font sizes declared below 12 pixels, and the long-deprecated <object>/<embed> plugins.
It also checks how many of your images declare srcset. Without it, a phone downloads the desktop-sized file; it looks small on screen while spending the full mobile data allowance.
How to use it
- 1
Enter the address of the page to check
One page per template is enough: a product page, a blog post, a contact page.
- 2
Start at the viewport line
Without width=device-width nothing else matters; the page opens at desktop width on a phone and everything shrinks.
- 3
Confirm zoom is allowed
Remove user-scalable=no or maximum-scale=1 if present. A visitor with low vision cannot enlarge the page.
- 4
Clear out the fixed widths
Legacy tables and inline styles are the usual source. Use percentages or max-width instead of pixels.
When to use it
- Before shipping a new theme or page template.
- When Search Console's mobile usability report shows errors and you want to find them in the HTML.
- When you take over an old site and need a quick measure of how much work it needs.
- When a page carries HTML pasted from an email or an ancient editor.
Reading the result
No viewport tag
The heaviest finding. One line fixes it: <meta name="viewport" content="width=device-width, initial-scale=1">
Zoom is blocked
An accessibility fault and a usability problem. It is usually added to stop a layout breaking, which hides the real issue.
Fixed width above 480 pixels
It creates horizontal scrolling on small screens. When a page slides sideways, one element is usually to blame.
Text below 12 pixels
Unreadable on a phone. Take 16 pixels as the floor for body copy and do not go under 14 for labels and footnotes.
No image declares srcset
Oversized files are going down to phones. Adding srcset and sizes cuts both the data and the load time.
Questions about the Mobile-Friendly Test
It does not; it reads the HTML and looks for structural signals. That finds the definite faults — viewport, fixed widths, font sizes — quickly. For visual problems such as tap target size or overlapping elements, you still need to open the page on a real phone.
Google's guidance is at least 48 pixels tall with at least 8 pixels between two targets. This tool cannot measure that from HTML, but it is the rule to follow in design; small, crowded buttons lower mobile conversion directly.
Not any more. Google recommends responsive design: one address, one set of content, a layout that adapts to the screen. A separate mobile site means two sets of content, two maintenance jobs and hreflang-style pairing problems.
Because Google uses mobile-first indexing, the effect is direct: the version being judged is the mobile one. Content that exists on desktop but is hidden on mobile can be treated as absent. It is not a penalty; the page is simply seen as less than it is.
Use it alongside these
The other tools in the same category. Run them together and you see the whole picture.
The tool found the problem. Now for the fix
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