Mobile-Friendliness Checker

Paste a URL to check its viewport meta tag and look for legacy technology that breaks entirely on mobile browsers. A static heuristic check, not a rendering-based test. Free, instant, no signup.

What this checks & how to fix it

It fetches the page and looks for a <meta name="viewport"> tag, checking whether one exists at all and whether its content includes width=device-width rather than a fixed pixel width. It separately flags a viewport that blocks pinch-to-zoom via user-scalable=no or a restrictive maximum-scale, and checks for obsolete, mobile-incompatible technology like <frameset> or Flash <embed>/<object> references.

How to fix what it finds

Add or correct the viewport tag in your page's <head>: <meta name="viewport" content="width=device-width, initial-scale=1"> is the standard, correct value for almost every site. Remove any user-scalable=no or restrictive maximum-scale from that same tag. Legacy frames and Flash content need to be replaced outright — there is no mobile-compatible fallback for either.

Frequently asked questions

Is this the same as Google's Mobile-Friendly Test?

No, and it's worth being upfront about the difference. Google's Mobile-Friendly Test actually renders the page like a mobile browser would and measures real things like tap-target sizes and text legibility. This tool only reads the raw, unrendered HTML — it checks for a viewport tag and a couple of technologies that are flatly incompatible with mobile browsers, but it can't see anything that depends on layout or rendering. For an authoritative, rendering-based verdict, use Google Search Console's mobile usability report or PageSpeed Insights.

What does the viewport meta tag actually do?

The <meta name="viewport"> tag tells a mobile browser how to size and scale the page. Without it, phones assume the page was built for a desktop screen (typically 980px wide) and render it at that width, then shrink the whole thing down to fit — leaving text microscopic until the visitor manually zooms in. content="width=device-width, initial-scale=1" tells the browser to match the page width to the actual screen width instead, which is the foundation of every responsive design.

Why does blocking pinch-to-zoom matter?

It's an accessibility issue, not just a convenience one. Some visitors — people with low vision, in particular — rely on pinch-to-zoom to read comfortably, even on a page that's otherwise perfectly responsive. Both Apple's and Google's own accessibility guidelines explicitly discourage setting user-scalable=no or a restrictive maximum-scale, precisely because it takes that option away from people who need it.

My site is built with a modern framework — why would it fail this?

A missing or misconfigured viewport tag is almost always a small oversight in a custom <head> or layout template, not a limitation of the framework itself. Every modern framework supports setting the viewport tag correctly; if this check flags it, look at whatever file controls your document's <head> — a custom meta-tags component, a layout file, or a CMS template setting — rather than assuming the framework is at fault.

It found no viewport tag, but my site looks fine on my phone. What's going on?

Some mobile browsers apply their own heuristics to compensate for a missing viewport tag, and a simple layout can happen to look acceptable anyway. That doesn't mean it's actually responsive — test on a few different devices and screen widths, and add the tag regardless. It's a one-line fix that removes the guesswork entirely.

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