What it is

Contrast checker that goes past the WCAG ratio. Enter a foreground and background pair and it simulates that combination through red-blindness, green-blindness, blue-yellow confusion and full colour blindness, plus cataracts, glaucoma, low vision, direct sunlight and night-shift filters. Built by Corey Ginnivan.

Why it earns a slot

It shows you the failure instead of a number, which is what actually changes your mind about a low-contrast grey. Useful for defending a colour choice to a client, or for killing your own.

Know before you commit

It checks one colour pair at a time, so it complements rather than replaces a whole-page automated audit like axe or Lighthouse.

Field notes

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Pricing snapshot

Free · open source

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Drop into your Lovable chat

Evaluate WhoCanUse (https://whocanuse.com) for this project, then use it only if it fits what we are already building.
Context: Contrast and vision simulator. Contrast checker that goes past the WCAG ratio. Enter a foreground and background pair and it simulates that combination through red-blindness, green-blindness, blue-yellow confusion and full colour blindness, plus cataracts, glaucoma, low vision, direct sunlight and night-shift filters. Built by Corey Ginnivan.
Reviewer notes (general, not written for this codebase): It shows you the failure instead of a number, which is what actually changes your mind about a low-contrast grey. Useful for defending a colour choice to a client, or for killing your own.
Watch out for: It checks one colour pair at a time, so it complements rather than replaces a whole-page automated audit like axe or Lighthouse.
Pricing: Free · open source
Rules: treat the notes above as background only. Do not assume a theme, style, layout or feature that is not already in this project — inspect the existing code first and ask me before changing visual direction.

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