Technical SEO
Mobile-Friendly Test: A Practical Checklist
Google retired its one-click mobile test in 2023. A reliable check now combines rendered content, field performance, responsive layout, accessible controls, and real-device journeys.
Google no longer offers a single pass-or-fail mobile testing tool. The useful replacement is a small test stack: inspect what Google can render, measure real-user performance, exercise the responsive layout, and complete the important journeys on physical devices.
The short version
A page is ready for mobile-first indexing when its mobile presentation preserves the primary content and search signals from desktop. A page is usable on mobile when people can also read, navigate, and complete tasks without layout or interaction failures. Test both.
What mobile-first indexing actually means
Google began mobile-first crawling in 2016 and announced that the transition was complete on October 31, 2023. Google now uses the mobile version of a site's content, crawled with its smartphone agent, for indexing and ranking. Responsive design is Google's recommended configuration because it serves the same HTML and URL across devices.
The practical requirement is parity. Google's current guidance says mobile pages should preserve important text, headings, images, alt text, titles, descriptions, structured data, and robots directives. Content can move into accordions or tabs for a smaller screen. It should still exist in the rendered mobile page and should not require a swipe, click, or typed action before Google can load it.
Sources: Google's mobile-first completion announcement and mobile-first indexing best practices.
The five-part mobile-friendly test
1. Inspect mobile content and search-signal parity
Start with Google Search Console's URL Inspection tool. Test the live URL and inspect the rendered HTML or screenshot with the smartphone crawler. Compare it with desktop for the elements that influence discovery and understanding.
- Primary copy, headings, links, images, and video
- Title, meta description, canonical, and robots directives
- Structured data, including the same entity identifiers and URLs
- Image alt text, captions, and descriptive filenames
- HTTP status and redirect destination for equivalent mobile URLs
2. Check the viewport, reflow, and zoom
Responsive pages need a viewport declaration so browsers lay out the page at the device width. Use this standard form:
<meta name="viewport" content="width=device-width, initial-scale=1">
Then test narrow widths and 200% zoom. Look for clipped text, overlapping controls, fixed-width tables, code blocks that force the whole page sideways, and menus that cannot be reached. Keep pinch zoom available. A layout that only works by preventing zoom creates an accessibility failure instead of fixing the responsive design.
3. Measure mobile Core Web Vitals in the field
Google's current Core Web Vitals are LCP, INP, and CLS. The recommended good thresholds are LCP within 2.5 seconds, INP at 200 milliseconds or less, and CLS at 0.1 or less. Evaluate all three at the 75th percentile of page loads, with mobile and desktop segmented.
PageSpeed Insights can show Chrome User Experience Report field data when a URL or origin has enough traffic. Its Lighthouse lab run is diagnostic, but one lab result does not prove that most mobile visitors receive the same experience. Use field data for the outcome and lab traces to investigate causes.
Sources: Google Search Central's Core Web Vitals guide and the Web Vitals measurement standard.
4. Test controls against WCAG 2.2
WCAG 2.2 Level AA sets a 24 by 24 CSS pixel minimum target area, with documented exceptions for spacing, inline links, equivalent controls, browser-controlled elements, and essential presentations. The enhanced Level AAA target is 44 by 44 CSS pixels. Larger targets remain sensible for frequent actions, destructive actions, and controls near screen edges.
- Open and close every menu, dialog, filter, and accordion
- Check that adjacent icon buttons do not trigger each other
- Verify visible focus and logical keyboard order
- Confirm error messages identify the field and the correction
- Test controls in portrait, landscape, and at increased text size
Source: W3C guidance for Target Size (Minimum).
5. Complete real-device journeys
Browser emulation is fast, but it cannot reproduce every browser chrome, on-screen keyboard, safe-area inset, network transition, permission prompt, or device performance constraint. Test the journeys tied to revenue or retention on at least one current iOS device and one current Android device.
- Landing page to signup or checkout
- Search, filtering, and pagination
- Login, password reset, and one-time-code entry
- Form validation with the software keyboard open
- Cookie, consent, age, or login dialogs
What replaced Google's retired Mobile-Friendly Test
Google retired the Mobile-Friendly Test, its API, and Search Console's Mobile Usability report on December 1, 2023. No single replacement covers the full job.
| Tool | Use it for | It does not prove |
|---|---|---|
| Search Console URL Inspection | Google's rendered page and indexing signals | Real-user usability or journey completion |
| PageSpeed Insights | Field Core Web Vitals and a Lighthouse lab diagnosis | Every template, browser, or interaction state |
| Browser device emulation | Responsive breakpoints, overflow, and fast visual checks | Physical-device input, browser chrome, or hardware limits |
| Physical devices | Touch, keyboards, orientation, dialogs, and complete journeys | Google's indexed representation |
| Foglift Technical Audit | Viewport plus broader SEO, performance, accessibility, security, and AI Readiness signals | Field Core Web Vitals or complete real-device journeys |
Source: Google's retirement notice.
Fix mobile failures in evidence order
| Failure | Evidence | First fix |
|---|---|---|
| Mobile content is missing from Google's render | URL Inspection render or HTML differs from desktop | Restore equivalent content, metadata, schema, and crawlable resources |
| Users cannot complete a key journey | Real-device reproduction, analytics drop-off, or support reports | Repair the blocking control, keyboard, dialog, or validation state |
| Mobile Core Web Vitals are poor | Mobile field data fails at the 75th percentile | Use a lab trace to isolate the LCP, INP, or CLS cause |
| Layout clips or scrolls sideways | Browser-width matrix or screenshot regression | Remove fixed widths and constrain tables, media, and code blocks |
| Targets are difficult to activate | WCAG audit plus physical-device test | Increase the target area or add compliant spacing |
Keep mobile usability and AI visibility separate
Mobile parity has a documented Google indexing role. That does not establish a direct causal link to citations from ChatGPT, Claude, or Perplexity. Google also says its AI search features use the same foundational technical requirements as normal Search, so indexable mobile content matters there without becoming a special AI ranking factor. See Google's current AI features guidance.
Use mobile tests to protect content access and user experience. Use an AI Visibility Check to measure whether an engine mentions or cites the brand for the prompts buyers actually ask. One metric should not stand in for the other.
Mobile-friendly release checklist
- Inspect the live mobile render in Search Console
- Confirm content, metadata, structured data, and robots parity
- Check the viewport, reflow, zoom, and horizontal overflow
- Review mobile field data for LCP, INP, and CLS
- Audit target size, focus, forms, and error handling
- Complete revenue-critical journeys on iOS and Android
- Retest after changes to templates, navigation, consent, or checkout
Frequently asked questions
Is Google's Mobile-Friendly Test still available?
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No. Google retired the Mobile-Friendly Test, its API, and Search Console's Mobile Usability report on December 1, 2023. Use URL Inspection for rendered indexing checks, PageSpeed Insights for mobile performance data, browser device emulation for layout checks, and real devices for interaction testing.
What does mobile-first indexing mean?
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Google uses the mobile version of a site's content, crawled with its smartphone agent, for indexing and ranking. Google completed the transition in October 2023. Important text, headings, images, metadata, structured data, and robots directives should remain equivalent across mobile and desktop presentations.
What is the minimum touch target size for mobile?
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WCAG 2.2 Level AA requires a target area of at least 24 by 24 CSS pixels, with exceptions for adequate spacing, inline links, equivalent controls, browser-controlled elements, and essential presentations. The enhanced Level AAA criterion uses 44 by 44 CSS pixels. Larger controls can still be the better design choice for frequent or high-consequence actions.
Does mobile-friendliness directly increase AI citations?
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There is no published evidence that passing a mobile usability test directly increases citations in ChatGPT, Claude, or Perplexity. Mobile content parity does affect what Google can index, and Google uses its normal Search requirements for AI features. Measure mobile usability and prompt-level AI citations as separate outcomes.
What does Foglift's Technical Audit check?
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Foglift's Technical Audit checks viewport configuration and the page's broader SEO, performance, accessibility, security, and AI Readiness signals. It does not replace real-device journey testing or field Core Web Vitals data, so use it with PageSpeed Insights, browser emulation, and physical-device checks.
Run the first audit
Start with Foglift's free Technical Audit to check the viewport and the page's broader technical signals. Then use URL Inspection, PageSpeed Insights, browser emulation, and physical devices for the evidence each of those tools uniquely supplies.
Sources & Further Reading
- Google Search Central: Mobile-first indexing is complete
- Google Search Central: Mobile site and mobile-first indexing best practices
- Google Search Central: Understanding Core Web Vitals
- web.dev: Web Vitals
- W3C WAI: Understanding WCAG 2.2 Target Size (Minimum)
- Google Search Central: A new mobile-friendly testing tool
- Google Search Central: AI features and your website
Fundamentals: Learn about GEO (Generative Engine Optimization) and AEO (Answer Engine Optimization) (the two frameworks for optimizing your content for AI search engines).