Accessibility
Watch it find the problems.
Below is a small business page with accessibility faults of seven ordinary kinds in it — the sort that reach a live site because they look fine to the person who built it. Nothing here is a recording. The report runs in your browser, right now, against the page in the frame.
It's produced by Squint, a browser extension that checks any page you're on against seven WCAG 2.2 AA success criteria. This page imports the exact file the extension ships, so you can see what it finds without installing anything. Switch the target to this page and it runs the same seven checks against the site you're standing on.
The report
The Copper Kettle — an invented tea room, broken on purposeOpen it on its own ↗
Checking…
How this works
The same file, three places
rules.js is a plain ES module with nochrome.* calls anywhere in it. That is what lets it run inside the extension's popup, inside this page, and inside a test suite identically — nothing here is a simulation of the extension, it's the extension's own logic given a different document to look at.
Two exemptions it gets right on purpose, because a checker that ignores them buries three real problems under thirty invented ones. A control's size is measured against the browser's own unstyled default before it can be called a failure. And a form control's clickable area includes its <label>when the label is larger — clicking a label operates its control, so that is genuinely what a person aims at.
What it does not check, and no automated tool can: whether alt text is accurate, whether the reading order makes sense, whether an error message is understandable. Those need a person and a screen reader. A tool that claimed them would be worth less than one that doesn't.