Online Tool Store
Color Blindness Simulator
Simulate protanopia, deuteranopia, tritanopia, or achromatopsia on any image, side by side with the original. Runs entirely in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
A sample image is shown below — upload your own to replace it.
Original
Simulated
How it works
- Upload an image, or use the sample.
- Choose a color vision deficiency type.
- Compare the original and simulated versions side by side, and download the result.
The method
Each pixel's R, G, B values are transformed by a 3×3 matrix specific to the deficiency type
New R = a·R + b·G + c·B, and similarly for new G and new B
FAQ
What types of color blindness does this simulate?
Protanopia (red-blind), deuteranopia (green-blind), tritanopia (blue-blind), and achromatopsia (full color blindness, grayscale) — the four most commonly referenced types when checking color accessibility.
How accurate is the simulation?
It applies well-known, commonly cited RGB transform matrices (derived from Brettel/Viénot color vision research) — a reasonable approximation for design review, though real color perception varies between individuals with the same diagnosis.
Why does this matter for design?
Roughly 1 in 12 men and 1 in 200 women have some form of color vision deficiency — relying only on color to convey information (like a red/green status indicator) can make an interface unusable for a meaningful share of visitors.
Is my image uploaded anywhere?
No — the simulation runs entirely in your browser using the Canvas API. Nothing is sent to a server.
How we compare
| Feature | Online Tool Store | Design tool plugins | Browser DevTools vision emulation |
|---|---|---|---|
| Exportable simulated image file | ✓ | Preview only, tied to the design tool | Live emulation only, no export |
| No install | ✓ | Requires the design tool | ✓ |
For a shareable image showing exactly how a design looks to a colorblind viewer, this beats a live-only preview you can't export or send to a teammate.