toolready. Color Blindness Simulator

Color Blindness Simulator

Preview your design through the most common color-vision deficiencies.

What does this do?

Shows your image as it would appear to people with the most common color- vision deficiencies, side-by-side with the original. Useful for sanity- checking charts, status indicators, design mockups, and "red means bad, green means good" UI patterns before they ship.

Which deficiencies are simulated?

  • Protanopia — no red cones. ~1% of men.
  • Deuteranopia — no green cones. ~1% of men. The most common form; often grouped with protanopia as "red-green color blindness."
  • Tritanopia — no blue cones. Very rare.
  • Achromatopsia — no color vision at all (rod monochromacy).

How accurate is the simulation?

Uses the matrix-based approach popularized by Brettel/Vienot/Mollon and used in Chrome DevTools' rendering panel. It's a good approximation, not a clinical model — actual perception varies between individuals and the severity of the condition.

Is my image uploaded?

No. The simulation runs per-pixel in your browser via canvas matrix multiplication.