Free Color Blindness Simulator
Upload an image or enter a URL · test under 4 CVD types · WCAG contrast checker included
Upload a design or enter a URL
See how your work looks to people with deuteranopia, protanopia, tritanopia, or achromatopsia. Nothing is sent to a server all processing is done in your browser.
Drop your image here, or click to browse
PNG · JPG · GIF · WebP · SVG up to 10 MB
Pro Tips
- Use high-resolution images (800px+) for clearer results
- Focus on UI elements that rely on color to convey information
- Charts, status indicators, and CTAs are the highest-risk areas
- 8% of men and 0.5% of women have some form of CVD
About This Color Blindness Simulator
This free color blindness simulator lets you preview how any design, image, or website appears to people with color vision deficiency (CVD). Upload an image file (PNG, JPG, SVG, GIF) or enter a live URL to see it through the lens of deuteranopia, protanopia, tritanopia, or achromatopsia.
Supported Color Vision Deficiency Types
- Deuteranopia Missing green-sensitive (M) cone cells. The most common CVD type. Greens and reds appear similar.
- Protanopia Missing red-sensitive (L) cone cells. Reds appear very dark or black.
- Tritanopia Missing blue-sensitive (S) cone cells. Blues appear green; yellows appear grey or violet.
- Achromatopsia All cone cells non-functional. The world appears in greyscale with no color information.
How to Use the Simulator
- Upload an image (PNG, JPG, SVG, GIF) or paste a live website URL into the input field.
- Select a CVD type from the dropdown deuteranopia, protanopia, tritanopia, or achromatopsia.
- Adjust the severity slider for mild-to-complete simulation of the condition.
- Click any two points on the image to check WCAG contrast ratios between those colors.
- Share results with a unique link you can send to team members or stakeholders.
WCAG Contrast Checker
Check whether your color combinations meet WCAG 2.2 accessibility standards. The built-in contrast checker calculates contrast ratios and shows AA (4.5:1 for normal text, 3:1 for large text) and AAA (7:1) pass/fail results all alongside the color blindness simulation in a single workflow.
Scientific Accuracy
Simulations use the peer-reviewed Machado, Oliveira & Fernandes (2009) color transformation matrices the same methodology used in professional design tools like Adobe Photoshop. All image processing happens locally in your browser. No images or data are ever uploaded to a server.