Mobile-Friendly Test: Is Your Website Ready for Mobile-First Indexing?

Over 60% of all web traffic now comes from mobile devices. Google switched to mobile-first indexing — meaning they crawl and rank the mobile version of your site, not the desktop version. If your website isn't mobile-friendly, you're losing both visitors and search rankings.

Over 60% of all web traffic now comes from mobile devices. Google switched to mobile-first indexing — meaning they crawl and rank the mobile version of your site, not the desktop version. If your website isn't mobile-friendly, you're losing both visitors and search rankings.

Test your website for free with Foglift — we check mobile-friendliness along with SEO, performance, security, and accessibility in one audit.

What Google's Mobile-First Indexing Means

Since 2019, Google has used mobile-first indexing for all websites. This means:

Google's crawler visits the mobile version of your site first
If content is only visible on desktop, Google may not index it
Mobile page speed directly impacts your rankings
Mobile usability issues can tank your position in search results

In other words: your mobile site IS your site as far as Google is concerned.

How to Test if Your Website is Mobile-Friendly

1. Check the Viewport Meta Tag

The single most important element for mobile responsiveness is the viewport meta tag:

<meta name="viewport" content="width=device-width, initial-scale=1">

Without this tag, mobile browsers will render your site at desktop width and shrink it to fit the screen — making text unreadable and buttons untappable. Foglift's free Website Audit checks for this automatically.

2. Test Core Web Vitals on Mobile

Google measures three Core Web Vitals specifically on mobile:

LCP (Largest Contentful Paint): Should be under 2.5 seconds. On mobile, this is often the hero image or above-the-fold content.
INP (Interaction to Next Paint): Should be under 200ms. Mobile devices have less processing power, so JavaScript-heavy pages perform worse.
CLS (Cumulative Layout Shift): Should be under 0.1. Images without dimensions and ads that load late are the biggest culprits on mobile.

3. Check Touch Target Sizes

Buttons and links should be at least 48x48 pixels with adequate spacing. Fingers are bigger than mouse cursors — if users can't tap your buttons easily, they'll leave. Common violations:

Small text links in navigation
Social media icons that are too small
Close buttons on popups
Links too close together in footer

4. Verify No Horizontal Scrolling

If any element extends beyond the viewport width, users get a horizontal scrollbar — a dead giveaway that your site isn't mobile-optimized. Common causes:

Fixed-width tables
Images without max-width: 100%
Inline code blocks with long lines
Absolute positioning without media queries

5. Test Text Readability

Text should be readable without zooming. Best practices:

Minimum 16px font size for body text
Line height of at least 1.5
Sufficient color contrast (4.5:1 ratio minimum)
No text on busy background images

Common Mobile-Friendliness Problems

Slow Mobile Load Times

Mobile connections are slower than desktop. Optimize by:

Compressing images (use WebP, target under 100KB each)
Lazy loading below-the-fold images
Minimizing JavaScript (code splitting, tree shaking)
Using a CDN for static assets
Enabling Gzip/Brotli compression

Content Hidden on Mobile

If you hide content on mobile using CSS (display: none on mobile), Google may not index it. With mobile-first indexing, hidden content effectively doesn't exist. Solutions:

Use collapsible sections instead of hiding content
Show all important content on mobile, even if reformatted
If content is desktop-only, it won't be indexed

Intrusive Interstitials

Google penalizes pages with intrusive interstitials (popups) on mobile. Avoid:

Full-screen popups that appear immediately on load
Interstitials that require dismissal before viewing content
Standalone interstitials that the user must dismiss before accessing the page

Exceptions: age verification, cookie consent, and login dialogs are fine.

Mobile-Friendly Checklist

Viewport meta tag present and correct
Core Web Vitals pass on mobile (LCP < 2.5s, INP < 200ms, CLS < 0.1)
All touch targets at least 48x48px
No horizontal scrolling on any page
Text readable without zooming (16px+ font size)
Images responsive with max-width: 100%
Forms usable on mobile (proper input types, large fields)
No intrusive interstitials
Same content visible on mobile as desktop
Navigation works with touch (hamburger menu, swipe gestures)

Frequently Asked Questions

What is mobile-first indexing?

Mobile-first indexing means Google predominantly uses the mobile version of your website for indexing and ranking. Google completed the switch to mobile-first indexing for all websites. If your site looks different on mobile versus desktop, Google sees the mobile version — so missing content, broken layouts, or slow loading on mobile directly hurts your rankings.

How do I test if my website is mobile-friendly?

Run a free website audit at foglift.io — it checks mobile viewport configuration, Core Web Vitals on mobile, touch target sizes, accessibility, and responsive design as part of a comprehensive scan. You can also use Chrome DevTools device mode (F12 → toggle device toolbar) to visually test on different screen sizes. Google's own Mobile-Friendly Test tool was deprecated in 2023.

What is the minimum touch target size for mobile?

Google recommends a minimum touch target size of 48x48 CSS pixels with at least 8px of spacing between targets. This ensures buttons and links are easy to tap without accidentally hitting adjacent elements. The WCAG 2.2 Level AA standard requires at least 24x24px targets, but 48x48px is the recommended best practice for mobile usability.

Does mobile-friendliness affect AI search visibility?

Mobile-friendliness doesn't directly affect AI citations in ChatGPT or Perplexity. However, AI crawlers (GPTBot, ClaudeBot, PerplexityBot) index the same content that Google indexes — and if your mobile version has less content than desktop due to poor responsive design, AI engines see less of your content. Additionally, Google AI Overviews consider page experience signals including mobile-friendliness.

Test Your Site Now

Foglift checks mobile-friendliness as part of our Website Audit. We analyze your viewport tag, Core Web Vitals, accessibility (including touch targets and contrast), and more — all in one audit.

Free audit: Full mobile-friendliness audit with all issues and AI action plan
Launch ($49/mo): Weekly mobile monitoring with email alerts
Growth ($129/mo): Advanced analysis with priority support

Fundamentals: Learn about GEO (Generative Engine Optimization) and AEO (Answer Engine Optimization) (the two frameworks for optimizing your content for AI search engines).