Web & Server Tools · Free tool
Mobile-Friendly Test
This tool simulates a mobile browser visit to your URL and reports rendering issues: viewport meta tag configuration, font size legibility at mobile scale, tap target spacing, content wider than the screen, and other mobile usability issues. Google's mobile-first indexing means the mobile version of your page is what they primarily evaluate.
SEO, GEO & AEO: why this checklist matters
Who should use this
Developers launching new pages, SEOs auditing sites for technical issues, and site owners after theme or template updates that may affect mobile rendering.
Rankings, AI answers, and citations
Mobile usability is a ranking factor through Google's Core Web Vitals and mobile-first indexing. Pages with significant mobile usability issues tend to underperform. For AI citation, if a page's mobile version is significantly worse than desktop, the content model sees a lower-quality version when crawling via mobile user agent.
What to verify before you ship
- Verify viewport meta tag is set: <meta name='viewport' content='width=device-width, initial-scale=1'>
- Font sizes should be at least 16px base to avoid zoom requirements
- Tap targets (buttons, links) should be at least 48x48px to hit accurately with a finger
- Images and media should not exceed the viewport width on any screen size
What you can expect next
Use this workflow on drafts and live URLs. For continuous monitoring across Google and AI surfaces, pair results with Linkstonic SEO audit, AI tracking, and TrueTrace.
Frequently asked questions
Written for search snippets, People Also Ask-style surfaces, and answer engines that quote short Q&A units.
What is mobile-first indexing?
Google primarily crawls and indexes the mobile version of pages. If your mobile page has less content than desktop, hides key sections, or blocks JavaScript and CSS resources, Google sees a degraded version and evaluates it accordingly.
My site looks fine on mobile — why does the test show issues?
'Looks fine' to a human eye isn't the same as passing Google's technical criteria. Common hidden issues: fonts that are technically below size thresholds, tap targets that are close but not meeting minimum size, or content that requires horizontal scrolling on narrow screens.
Does mobile page speed affect rankings?
Yes. Core Web Vitals (LCP, FID/INP, CLS) are measured on mobile and are confirmed ranking signals. Slow mobile loading is the most common failing area for sites in competitive categories.
Is a separate mobile site or responsive design better for SEO?
Google recommends responsive design (one URL, CSS adapts to viewport). Separate mobile sites (m.subdomain) require careful canonical and hreflang configuration. Dynamic serving is also supported but more complex to implement correctly.