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Mobile-Friendly Checker
Check viewport, tap targets, font sizes and fixed widths.
About the Mobile-Friendly Checker
The page is requested with a mobile user agent and checked for the things that actually break on a phone: a missing or misconfigured viewport tag, fixed pixel widths that force horizontal scrolling, font sizes below the readable threshold, tap targets packed too close together, and interstitials that cover the content on load.
The viewport tag is the one that matters most and the one most often wrong. Without width=device-width the browser renders at desktop width and scales the whole page down, which is why some sites look like a shrunken newspaper. Setting user-scalable=no is worse: it blocks pinch-zoom, which is an accessibility failure as much as a usability one.
Since Google indexes the mobile version of your site rather than the desktop one, anything the mobile page omits — text hidden behind a tab, images only loaded on wide screens, structured data present on desktop only — is effectively not on your site at all.
Common questions
Why does the checker flag my site when it looks fine on my phone?
It's tested with a mobile user agent against the raw response, so issues introduced by client-side scripts after load — like a menu that requires JavaScript — may show differently than what you see.
Does mobile-friendliness affect rankings?
Yes, directly. Google indexes the mobile version of your site as the primary version, so anything missing on mobile is effectively missing from the index.
What's the most common failure this catches?
A missing or misconfigured viewport tag. Without width=device-width, the browser renders the page at desktop width and shrinks it, which is why some mobile pages look like a tiny newspaper.