AZ Tools

Color Blindness Simulator

Color

Drop a screenshot of a chart, dashboard, or design and switch between 8 simulated views: normal, three full-color blindness types (protanopia, deuteranopia, tritanopia), three partial color-weakness types (protanomaly, deuteranomaly, tritanomaly), and full monochrome (achromatopsia). Each is rendered by applying the corresponding linear transform per pixel via Canvas — fast, fully offline. Useful for sanity-checking charts and palettes before shipping.

Vision type

About the simulation

Color blindness simulation uses linear RGB transforms (Brettel/Viénot-style matrices). It's an approximation of how the image might appear, not a clinical replica. Always validate critical accessibility decisions with real users or formal contrast tooling like WCAG checkers.

How to use

  1. Drop a screenshot of a chart, palette, or design.
  2. Click each chip to see the image rendered for that vision type.
  3. Download a copy of the current simulation to share with the team.

Frequently asked questions

Are these scientifically accurate?
They're approximations based on widely-cited linear RGB transforms (Brettel / Viénot / Mollon style). Real human vision varies; treat the previews as 'how this might look', not exact.
Which types affect the most people?
Deuteranomaly (mild green weakness) is by far the most common — about 5% of men. Protanomaly and protan/deutan dichromacy together account for most CVD.
What's achromatopsia?
Complete color blindness — the world is seen in shades of gray. Very rare, but a good worst-case check: if the design still works in pure grayscale, it'll work for everyone.
Why is my image uploaded?
It isn't — the simulation runs locally with Canvas. The image and the matrices both stay in your browser.

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