Paste (Ctrl+V), drop, or browse — see how your image looks to people with CVD.
Color vision deficiency (CVD) affects approximately 8% of males and 0.5% of females. There are several types, each caused by missing or malfunctioning cone cells in the retina.
This simulator applies scientifically-accurate color transformation matrices (Brettel, Viénot & Mollon, 1997) so you can see exactly how your designs appear to affected users.
Use this tool alongside the Contrast Checker to ensure your UI passes WCAG AA and AAA guidelines for all users.
The "All types" grid view lets you instantly see all 8 simulations side by side — perfect for design reviews and accessibility audits.
All image processing happens locally in your browser using the Canvas API. Your images are never uploaded to any server, never stored, and never transmitted.
The simulator uses the Brettel-Viénot-Mollon (1997) and Machado (2009) color transformation matrices — the same scientific models used by professional accessibility tools like Coblis and Adobe's Color Accessibility tools.
The severity slider lets you blend between normal vision (0%) and the full simulation (100%). This is useful for simulating anomalous trichromacy (partial deficiency), like deuteranomaly or protanomaly, at different severity levels.
Deuteranomaly (weak green cones) is the most common form, affecting roughly 5% of males. Deuteranopia and protanopia together affect about 2% of males. Tritanopia and achromatopsia are much rarer.
Yes — click "Download simulated image" to save the current simulation as a PNG. You can also download a grid of all 8 types at once using "Download all types".
JPG, PNG, WebP, BMP, GIF, and SVG — or paste directly from your clipboard with Ctrl+V.
Uses Brettel-Viénot-Mollon (1997) dichromacy and Machado (2009) anomaly matrices for maximum accuracy.
Drag the divider to compare original and simulated versions of the same image pixel-for-pixel.
See all 8 simulations at once. Click any cell to jump to that vision type in split view.
Blend between normal and full simulation to model anomalous trichromacy at any severity level.