Home / Design / Color Blindness Simulator
Color Blindness Simulator
Preview designs, charts and photos as people with protanopia, deuteranopia, tritanopia and achromatopsia see them.
Free, no uploads, no sign-up. Runs 100% in your browser.
How Color Blindness Simulator works
Colours are converted to linear RGB and transformed with the Machado, Oliveira and Fernandes (2009) simulation matrices, which model how each type of colour vision deficiency shifts colours. Severity blends between normal and full deficiency.
Input: PNG, JPG, WEBP, AVIF. Output: PNG, JPG, WEBP.
How to use Color Blindness Simulator
- Drop a screenshot, chart or photo.
- Pick a type of colour vision, or view all at once.
- Download the simulated image or the comparison grid.
Tips
- About 1 in 12 men has some colour vision deficiency. Deuteranomaly is the most common.
- If two colours look the same in the simulation, add labels or patterns.
Color Blindness Simulator FAQ
- Is my file uploaded?
- No. Everything runs in this browser tab on your own device. Engines are downloaded once and cached, but your files never leave your computer.
- Are my files uploaded?
- No. This tool runs entirely in your browser tab. Files are read from your disk into memory and the result is generated locally.
- Is it free? Are there limits or watermarks?
- Free and open source (MIT). There are no file-size caps, daily quotas, accounts or watermarks.
- Does it work offline?
- Yes, once the page (and any engine it needs) has loaded, it keeps working without a connection thanks to the service worker cache.
Related tools
- Color Palette Extractor: Extract dominant colors and export CSS/Tailwind palettes.
- Color Converter & Contrast: HEX, RGB, HSL, OKLCH conversion and WCAG contrast checks.
- Compare Images: Compare two images with a slider, side by side, onion skin or a pixel difference heatmap, with percent changed and PSNR.
- Gradient Generator: Design linear, radial and conic gradients and copy CSS.