Color Blindness Simulator

A FREE, offline, multi-language app.

This is a free tool for designers, developers, educators, and anyone curious about how colorblind people see the world.

Around 1 in 12 men and 1 in 200 women have some form of color vision deficiency. If you design websites, apps, charts, signage, maps, or educational materials, your work is being seen very differently by a meaningful slice of your audience. Color Vision helps you check that.

SIMULATE 8 TYPES OF COLOR BLINDNESS: Apply scientifically-grounded simulation filters to any image:

- Deuteranomaly & Deuteranopia (red-green, most common — ~5% of men)
- Protanomaly & Protanopia (red-green, missing red receptors)
- Tritanomaly & Tritanopia (rare blue-yellow deficiency)
- Achromatopsia & Achromatomaly (total or partial loss of color)

Use the severity slider to see the full spectrum from mild deficiency to full dichromacy.

INSTANT COMPARISON: Side-by-side preview shows the original next to the simulated version. Or jump to the Compare tab to see all 8 types in a single grid.

DALTONIZATION (CORRECTION): The opposite of simulation: a correction filter that redistributes problematic color information into channels the colorblind viewer can still see. Useful for colorblind users themselves, and for designers wanting to understand how correction works.

WCAG CONTRAST CHECKER: Pick a foreground and background color and instantly see whether your combination passes WCAG 2.1 AA, AA Large, and AAA standards.

PALETTE ANALYZER: Drop in your design's color palette (up to 8 colors). The tool simulates each color under every vision type and flags pairs that become indistinguishable — exactly the colors that will trip up your colorblind users.

COLOR VISION TESTER: Pick any single color and see all 9 perceptions side by side. Great for understanding how a specific brand color shifts.

FOR EDUCATORS: Built-in Ishihara-style test plate, color wheel, swatch palette, and landscape scene make it easy to demonstrate color vision deficiency to students or clients.

PRIVATE & FREE: All processing happens on your device. No images leave your phone. No accounts, free.