---
title: "Color Blindness Simulator"
description: "See a palette or a screenshot the way protanopia, deuteranopia, tritanopia and achromatopsia render it. Runs in your browser; the image is never uploaded."
url: https://findutils.com/design/color-blindness-simulator/
category: design
---

# Color Blindness Simulator

See a palette or a screenshot the way protanopia, deuteranopia, tritanopia and achromatopsia render it. Runs in your browser; the image is never uploaded.

**Use this tool:** [Color Blindness Simulator](https://findutils.com/design/color-blindness-simulator/)

## Programmatic access

- Browser-only: this tool works on a file, the DOM, or a browser API and has no REST or MCP id.

## Why simulate colour vision deficiency?

Roughly one in twelve men and one in two hundred women has some form of colour vision deficiency, and the most common kinds compress red and green towards the same yellow-brown. A chart whose series are red and green, a form that marks errors only by turning a border red, a status badge that relies on green meaning fine - each of these can be unreadable to a reader you never hear from. Seeing the palette rendered the way those readers see it takes seconds and is far more direct than reasoning about it in the abstract.

## Frequently Asked Questions

### Does this tell me if my palette is accessible?

No, and it deliberately does not claim to. It shows how colours may appear under four deficiencies. Accessibility standards are about measured contrast ratios, which the Contrast Checker reports. A palette can be perfectly distinguishable here and still fail contrast.

### Which deficiency should I check first?

Deuteranopia. It is the most common form and it flattens the red-green distinction that most interfaces lean on for success and error states.

### How accurate is the simulation?

It uses the standard matrix approximations for each dichromacy, which are good enough to reveal confusable pairs. They are not a medical model, they do not cover anomalous trichromacy where a cone is shifted rather than absent, and individual vision varies.

### Is my image uploaded?

No. The file is read from your device and processed in a canvas inside the tab. No request carries the image. Third-party analytics and ads load on the page, as on the rest of the site.

### What do I do about two colours that look the same?

Give the distinction a second carrier. Change one colour's lightness rather than its hue, or add an icon, a label, a dash pattern or a position difference so the meaning does not rest on colour alone.

### Why does the achromatopsia strip look like greyscale?

Because it is a luminance conversion, which is what a complete absence of colour perception approximates. It doubles as a preview of how the palette will print in black and white.

### Can it simulate partial deficiency?

Not yet. It models the dichromacies, where a cone type is missing. Anomalous trichromacy, which is more common and milder, sits between normal vision and these strips.

### Is it free?

Yes. No signup, no limits, and no upload.

## Related Tools

- [Contrast Checker](https://findutils.com/design/contrast-checker/)
- [Color Palette Generator](https://findutils.com/design/color-palette-generator/)
- [Color Converter](https://findutils.com/design/color-converter/)
- [Image Color Extractor](https://findutils.com/design/image-color-extractor/)
- [Gradient Generator](https://findutils.com/design/gradient-generator/)
- [Color Name Finder](https://findutils.com/design/color-name-finder/)