About Hue Shall Not Pass
A contrast checker that leads with the answer, not the arithmetic.
Why this exists
Every colour contrast checker on the web will happily tell you that your text scores 4.32:1. Almost none of them will tell you what that means, which is the only thing most people actually want to know: can people read this, or not?
That gap matters. The people choosing colours — designers picking a palette, marketers building an email, founders settling on a button colour — mostly aren't accessibility specialists. They bounce off "AA Fail, AAA Fail," or worse, they misread a "Large Text Pass" as a green light and ship something a lot of people genuinely can't read.
Hue Shall Not Pass answers the real question first, in a plain sentence, and keeps the ratio and the WCAG detail underneath as supporting evidence for the people who want it. It's free, it works instantly, it needs no account, and every number it produces follows the WCAG 2.1 specification exactly — an accessibility tool that can't do its own maths correctly would be a bad joke.
Who made it
It's built and maintained by Mark Thurman. Here's the short version, and the tool page carries the same byline because you should always know who's telling you your colours are fine.
What it won't do
On purpose, it's small. It checks two solid colours and tells you whether they work. It doesn't scan whole sites, generate palettes, or simulate colour blindness (that last one is on the list). If you want the deeper background, the plain-English guide covers why contrast matters, what WCAG actually says, and how to fix a failing pair.
Say hello
Found a bug, disagree with a verdict, or want a feature? Get in touch — there's a real, monitored inbox behind it.