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Mobile-Friendly Tester

Paste HTML and run static checks for the mobile-readiness signals Google's bots look for — viewport meta, tap target sizes, font sizes, and horizontal-scroll triggers.

Mobile-Friendly Tester

Paste HTML and run static checks for the mobile-readiness signals Google's bots look for — viewport meta, tap target sizes, font sizes, and horizontal-scroll triggers.

Why a Static Mobile Check Still Has Value

Real mobile testing runs the page in a headless browser, measures rendering, and reports layout shift. This tool does not replace that — Lighthouse and Chrome DevTools are still the right call for final verification. What a static checker does well is the catch-it-before-you-deploy pass: spotting a missing viewport meta in a hand-edited template, a 10-pixel font size buried in inline styles, links spaced four pixels apart that would fail Google's tap target rule. Those are template-level bugs that Lighthouse would flag too — but only after you have already loaded the page in a slow simulation. A static check finds them in seconds, in the editor, with no server roundtrip. Use alongside the Core Web Vitals Cheatsheet for the runtime side.

How the Heuristics Score Your HTML

The tool runs four passes over the pasted HTML. Pass one is meta — does the head contain `<meta name='viewport'>` and is its content value a reasonable `width=device-width, initial-scale=1`? Common bugs flagged: missing tag entirely, `initial-scale=1` without `width=device-width`, fixed pixel widths, `user-scalable=no` (which blocks accessibility zoom). Pass two is touch targets — every `<a>` and `<button>` is checked for inline width/height styles below 44 pixels and the surrounding markup is scanned for spacing rules under 8 pixels. Pass three is typography — body text below 14 pixels and explicit `font-size` declarations under that threshold are flagged. Pass four is layout — fixed pixel widths over 360 on top-level containers (the rough minimum mobile viewport) and elements with `overflow: visible` and inline widths exceeding that. Each pass reports as a separate section with line-referenced findings.

Frequently Asked Questions

Does this run a real device emulation?+
No. The tool reads HTML and inline styles statically and applies heuristic thresholds. For true device behavior — JavaScript runtime, dynamic resizing, web font swap — you still want Lighthouse or Chrome DevTools.
What viewport content value should I use?+
`width=device-width, initial-scale=1` is the standard. Avoid `user-scalable=no` and `maximum-scale=1` — both block pinch-to-zoom and fail accessibility audits. Modern responsive design does not need them.
Why is 44 pixels the tap target threshold?+
Apple's Human Interface Guidelines set it; Material Design uses 48 pixels for the same reason. Either works; the tool defaults to 44 to match Google's mobile-friendly check.
My body font is 16 pixels but the tool flags it — why?+
Most likely an inline style or a media query is overriding it at smaller breakpoints. Search the HTML for `font-size:` and check whether any selector applies to body or to the elements being flagged.
Does it handle CSS in external stylesheets?+
Only inline `<style>` blocks and inline `style=` attributes are parsed. External stylesheets are out of scope because the tool does not fetch URLs. Paste the relevant rules inline if you need the check.
What counts as horizontal-scroll risk?+
A top-level element with explicit pixel width above 360 (the smallest mainstream mobile viewport) and an ancestor without `overflow-x: hidden`. The flag is conservative; some valid designs use horizontal scrolling intentionally.
Should every link be 44 pixels tall?+
No — inline links inside body text are exempt. The 44-pixel rule applies to standalone interactive elements like nav links, buttons, and card tap targets. The tool follows that distinction.
Will my page pass Google's mobile-friendly test if this tool passes?+
Likely yes for static signals, but Google's test also runs JavaScript and checks resource availability. Use this for fast pre-flight; treat Google's test as the final word.

Built by Derek Giordano · Part of Ultimate Design Tools

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