Colorblind simulator

Colorblindness Simulator for Images

See how your image looks to people with protanopia, deuteranopia, or tritanopia — a fast accessibility check.

Drop an image to pick colors

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PNG · JPG · WebP — colors read on your device

3 CVD typesExport the result100% free PNG · JPG · WebP

Colorblindness Simulator for Images

Roughly one in twelve men and one in two hundred women have some form of color vision deficiency (CVD). If your charts, dashboards, maps, or UI rely on color alone to carry meaning, a sizable share of your audience may not see the distinction you intended. This simulator re-renders an image the way it would appear with the three common types of color blindness, so you can check your work in seconds.

It covers protanopia and deuteranopia (the two red–green deficiencies, by far the most common) and tritanopia (a rarer blue–yellow deficiency). The transformation is applied in linear light for a perceptually reasonable approximation — close enough to reveal the problems that matter, like a red/green status indicator collapsing into two near-identical tones.

Use it on legends, call-to-action buttons, heatmaps, and infographics. If two categories become hard to tell apart in any simulation, add a non-color cue — a label, pattern, icon, or shape — so the meaning survives for everyone. You can export the simulated image to share the issue with your team.

How to simulate colorblindness on an image

  1. Add your image — a chart, UI screenshot, or graphic works well.
  2. Pick a type — protanopia, deuteranopia, or tritanopia.
  3. Compare — the preview re-renders so you can spot lost contrast.
  4. Download — save the simulated image as PNG, JPG, or WebP.

Tip: never rely on color alone

The most robust fix is redundancy: pair every color with a second signal — text, an icon, a pattern, or position. That way the information is legible regardless of how a viewer perceives color.

Colourblind simulator: how it works

What it does
Re-renders an image the way it would appear to someone with one of the common types of colour vision deficiency, as a fast accessibility check.
Colour output
A simulated version of the image for protanopia or deuteranopia (the two red–green deficiencies) or tritanopia (a rarer blue–yellow deficiency), which you can download as PNG, JPG, or WebP.
How it works
The transformation uses Brettel/Viénot-style colour matrices applied in linear light (the image is converted out of gamma-encoded sRGB first), which is a perceptually reasonable approximation. It is meant for spotting accessibility problems — like a red/green status indicator collapsing into two near-identical tones — not for clinical diagnosis.

What you can use it for

  • Checking that charts, dashboards, and maps don't rely on colour alone to carry meaning.
  • Testing whether legend entries stay distinguishable when similar hues sit side by side.
  • Reviewing call-to-action buttons, heatmaps, and infographics before publishing.
  • Exporting the simulated image to document an accessibility issue for your team.

Tip: The most robust fix is redundancy — pair every colour with a second signal such as a label, icon, pattern, or position — so the meaning survives no matter how a viewer perceives colour. Roughly 1 in 12 men have some form of colour vision deficiency, so this affects a real share of any audience.

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Frequently asked questions

What types of color blindness can I simulate?

Protanopia and deuteranopia (red–green) and tritanopia (blue–yellow) — the three most common forms of color vision deficiency.

How accurate is the simulation?

It's a perceptually reasonable approximation applied in linear light. It's meant for spotting accessibility problems, not for clinical diagnosis.

Why does my chart look fine but my legend doesn't?

Legends often pack similar hues close together. Under red–green simulation those can collapse into near-identical tones — a sign you should add labels or patterns.

Can I save the simulated image?

Yes. Export it as PNG, JPG, or WebP to document the issue or share it with your team.

Where is my image processed?

It happens in your browser, so the result is created on your own device. How any data associated with the tool is handled is described in our privacy policy.

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