Color Blindness Simulator - Color Accessibility Testing
Test your designs for color blindness: protanopia, deuteranopia, tritanopia.
Test de palette de couleurs
Vision normale
Sans simulation
Protanopie
Absence de cônes rouges (~1% hommes)
Deutéranopie
Absence de cônes verts (~6% hommes)
Tritanopie
Absence de cônes bleus (rare)
Achromatopsie
Vision en noir et blanc (très rare)
Test sur image
Types de daltonisme
Supported formats
How it works
Upload your image or enter your colors
Select the type of color blindness to simulate
View the rendering for each deficiency
Adjust your colors if necessary
Privacy guaranteed
Simulation done locally. Your images never leave your device.
Understanding color blindness and its types
Color blindness affects color perception. Affected people don't see colors the same way. This can make some designs unreadable or confusing. Our simulator lets you see your design as a colorblind person would see it. Simulate the main color blindness types (protanopia, deuteranopia, tritanopia, achromatopsia) to test the visual accessibility of your interface and improve inclusivity. Instantly convert between HEX, RGB, HSL, HSV and CMYK, adjust hue, saturation and lightness with real-time preview and check WCAG AA/AAA contrast for sRGB-compliant accessibility.
Protanopia: red deficiency
Affected people don't perceive red and confuse it with green or brown. Represents about 1% of men. Red text on green background is particularly problematic.
Deuteranopia: green deficiency
The most common form (6% of men). Greens are confused with reds. Status indicators (green = OK, red = error) should be accompanied by icons.
Tritanopia: blue deficiency
Rarer, affects blue and yellow perception. Blues appear green and yellows appear pink or purple. Important for charts and infographics.
Test your designs for accessibility
Import your mockups, screenshots or images and view them instantly through different color blindness filters. Identify problematic areas where colors blend and make necessary corrections.
Best practices for accessible design
Never rely solely on color to communicate information. Use icons, text, shapes or patterns as complement. Ensure sufficient contrast (4.5:1 ratio minimum). Always test with our simulator.
WCAG compliance and legal obligations
WCAG 2.1 (Web Content Accessibility Guidelines) require that color not be the only means of conveying information (criterion 1.4.1). Our tool helps you verify compliance and avoid accessibility issues.
Free and privacy-friendly simulator
Our simulator works entirely in your browser. Your images are never sent to our servers. Use it for free, without limits and without signup for all your projects.
Color blindness and digital accessibility in business
8% of men and 0.5% of women are color blind. Testing your site in the three main modes (protanopia, deuteranopia, tritanopia) is mandatory for European public sites (RGAA, EAA 2025) and a commercial asset.