Mobile-Friendly Test
Test any website for mobile usability issues. Instantly check viewport configuration, tap target sizes, font readability, and mobile performance score — the same signals Google uses for mobile-first indexing.
Uses Google Lighthouse mobile simulation (4G throttled). Takes 10–30 seconds.
How to Use the Mobile-Friendly Test
Enter any URL in the field above and click Test Mobile Friendliness. The tool calls the Google PageSpeed Insights API with a mobile simulation and returns results in 10–30 seconds. No login required.
Results include two Lighthouse scores — Mobile Performance and Mobile SEO — plus a pass/fail card for each key mobile signal. You also get the top opportunities that would most improve load time on mobile devices.
The Four Core Mobile Signals
Viewport Meta Tag
A correctly set viewport tag (<meta name="viewport" content="width=device-width, initial-scale=1">) tells the browser how to scale the page. Without it, mobile browsers render the desktop version and shrink it down, making text tiny.
Tap Targets
Buttons, links, and form elements must be large enough to tap accurately on a touchscreen. Google recommends a minimum size of 48×48 CSS pixels with 8px of separation between targets.
Font Size
Body text should be at least 16px on mobile. Smaller text forces users to pinch-to-zoom, hurting usability. Google flags pages where the majority of text is too small.
Content Width
All content should fit within the viewport width. Horizontal scrolling is a signal of broken mobile layout. Use relative units (%, vw) instead of fixed pixel widths for fluid layouts.
Why Mobile-Friendliness Matters for SEO
Google switched to mobile-first indexing in 2019, meaning the mobile version of your site is what Google primarily uses to understand and rank your content. If your mobile experience is poor — slow load times, broken layout, or tiny text — that directly impacts your rankings in both mobile and desktop search results.
Beyond rankings, mobile usability drives conversions. Studies consistently show that users who encounter friction on mobile (slow loads, hard-to-tap buttons, horizontal scroll) leave immediately. A poor mobile experience hurts both your SEO and your revenue.
How to Improve Your Mobile Score
Start with the opportunities listed in the results. The most impactful improvements are usually: optimising images (use WebP, add explicit width/height, lazy-load below-the-fold images), reducing render-blocking JavaScript (defer or async non-critical scripts), and enabling a CDN with proper cache headers. For layout issues like tap targets and content width, audit your CSS for fixed pixel widths and ensure your responsive breakpoints cover small screens (320px–375px).
Frequently Asked Questions
What makes a website mobile-friendly?
A mobile-friendly website includes four essential elements: a proper viewport meta tag (so the browser scales the layout correctly), tap targets that are at least 48×48 px with adequate spacing, readable font sizes (body text should be at least 16px to avoid requiring zoom), and content that fits within the screen width without horizontal scrolling. Fast load time on mobile networks is equally important, since Google simulates a 4G connection during its mobile assessment.
How is the mobile score calculated?
The score uses Google's Lighthouse engine via the PageSpeed Insights API — the same methodology Google uses to assess mobile UX. Lighthouse simulates a mid-tier Android device on a 4G network and measures real performance metrics. The performance score is a weighted aggregate of LCP, FCP, Speed Index, TBT, and CLS. The SEO score checks for technical signals like viewport meta tags, robots directives, and link text. Both scores range from 0–100.
Will a low mobile score hurt SEO?
Yes. Google uses mobile-first indexing, which means it predominantly uses the mobile version of your content for indexing and ranking. If your mobile experience is poor, it directly affects how Google perceives your overall site quality. Core Web Vitals (which are heavily influenced by mobile performance) are also a confirmed ranking signal since 2021. A low mobile score, especially for LCP and CLS, can suppress your rankings in competitive queries.
What's the difference between mobile and desktop score?
Mobile tests apply two major handicaps that desktop tests don't: CPU throttling (simulating a mid-tier device at 4× slowdown) and network throttling (simulating a 4G connection at ~1.6 Mbps download). Desktop tests run without any throttling. This is why mobile scores are typically 10–30 points lower than desktop scores for the same page. Mobile testing also evaluates touch-specific requirements like tap target size and font readability, which don't apply to desktop.
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