Color Blindness Simulator: see your design through other eyes
Upload or paste a screenshot, chart or photo and compare it with protanopia, deuteranopia, tritanopia, their milder forms and achromatopsia. A palette check flags colors that blur together. Runs in your browser.
Free · No sign-upHow to use Color Blindness Simulator
- 1. Drop an image or screenshot, paste one with Ctrl+V, or press Try a sample image.
- 2. Pick a color vision type. For the “-anomaly” types, set the Severity.
- 3. Drag the split slider, switch to Side by side, or open All types to see every simulation at once.
- 4. Run the Palette check on your brand or chart colors, then download a PNG, a comparison sheet or a ZIP of all types.
Frequently asked questions
How accurate is this color blindness simulator?
It uses the physiologically based model by Machado, Oliveira and Fernandes (IEEE TVCG, 2009), applied in linear RGB as the model intends. It is a good approximation for design reviews, but real color vision varies between people and screens, so also test with real users.
Which types of color blindness can I simulate?
Protanopia and protanomaly (red), deuteranopia and deuteranomaly (green, the most common), tritanopia and tritanomaly (blue) and achromatopsia (no color). The milder anomaly types have a severity slider from 10% to 100%.
Is my image uploaded?
No. The image is processed with a canvas in your browser and never leaves your device. You can even use the tool offline once the page has loaded.
What does the palette check do?
It simulates every color in your palette for each type and measures the CIEDE2000 difference between each pair. Pairs that are clearly different for normal vision but fall under ΔE 10 are flagged as hard to tell apart (under 5: they look the same).
Does this help with the European Accessibility Act and WCAG?
The EAA, enforced since June 2025, relies on EN 301 549, which includes WCAG. This tool helps with WCAG 1.4.1 Use of Color. For text and UI contrast (1.4.3, 1.4.11), use our Color Contrast Checker as well.
How common is color blindness?
About 1 in 12 men and 1 in 200 women of Northern European descent have a red-green deficiency; deuteranomaly alone affects about 5% of men. Blue-yellow types and complete color blindness are rare.