Mobile-friendly test

See any page the way a phone does (an iPhone-sized screen in real Chrome) and find what makes it hard to use: sideways scrolling and the element that causes it, a missing viewport tag, text too small to read, broken images and JavaScript errors.

Free: 10 tests a day, no signup. Takes about 10 seconds.

What it checks

  • Viewport tag. Without width=device-width, phones render the desktop layout 980px wide and shrink it.
  • Fits the screen. Content wider than the screen makes the page slide sideways. The test names the elements that stick out, and ignores content that's properly clipped.
  • Readable text. Fails when more than 40% of the text is under 12px, the threshold Lighthouse uses.
  • Broken images and JavaScript errors while the page loads. Tracking pixels and hidden images don't count.

Google retired its Mobile-Friendly Test in December 2023. This runs the same kind of check in an up-to-date Chromium with the phone's real screen size and touch support.

Test every deploy

The same check is one API call, on phone, tablet and desktop at once, with the problems in plain language next to each screenshot:

curl "https://shotlane.dev/v1/check?url=example.com" \
  -H "X-API-Key: $KEY"

Or add the GitHub Action to test every preview deploy and comment on the pull request. See the docs.

100 free renders a month · no credit card · key shown instantly

FAQ

What breaks most often on phones?

When I tested 1,000 popular websites on a phone, 3% scrolled sideways, mostly by a few pixels. The usual causes: a Bootstrap .row outside a .container, carousels and horizontal menus whose wrapper doesn't clip them, and elements with a fixed width. 2% had no viewport tag at all.

I set overflow-x: hidden on body. Why does it still scroll sideways?

On phones, overflow-x: hidden on body alone doesn't stop panning, so the hidden part is still reachable. Put it on both html and body, or better, on a wrapper around the content, and fix the element that's too wide.

Does this affect my Google ranking?

Google indexes the mobile version of your pages, so content that's cut off, unreadable or broken on a phone is what Google sees too. A pass here means the basics are right; it isn't a ranking score.

Can it test a page behind a login, or on localhost?

Not this free tool: it only opens public pages. The API can send cookies or headers, or render HTML you pass in.