How to Simulate Color Blindness

Test your designs for color blindness. Simulate protanopia, deuteranopia, tritanopia, and more. Free accessibility testing tool.

Open Color Blindness Simulator →

Step-by-Step Guide

1

Upload or select an image

Upload any image or design screenshot you want to test. You can also enter a URL to load an image from the web, or use the color picker to test specific colors.

2

Choose a vision type

Select from different types of color vision deficiency: Protanopia (red-blind), Deuteranopia (green-blind), Tritanopia (blue-blind), or Achromatopsia (complete color blindness). Each type shows how users with that condition perceive colors.

3

Compare side by side

View the original and simulated versions side by side. This helps you identify problematic color combinations that might be indistinguishable for color-blind users.

4

Adjust your design

Use the insights to improve your design. Add patterns, textures, or labels alongside colors. Test again until your design is accessible to all users.

Try It Now — Free

No signup, no download. Runs entirely in your browser.

Open Color Blindness Simulator

Frequently Asked Questions

Why test for color blindness?
About 8% of men and 0.5% of women have some form of color vision deficiency. Testing ensures your designs are accessible to all users, not just those with normal color vision.
What are the main types of color blindness?
Protanopia and protanomaly affect red perception. Deuteranopia and deuteranomaly affect green perception (most common). Tritanopia affects blue-yellow perception (rare). Achromatopsia is complete color blindness (very rare).
How do I make designs color-blind friendly?
Never use color alone to convey information. Add patterns, shapes, or text labels. Use high contrast ratios. Test with simulators like this one. Tools like Color Oracle and Stark can also help.
Related Reference

CSS Flexbox Cheat Sheet

View Cheat Sheet →

More Guides