Protanopia
Absence or reduced sensitivity to red. Reds look darker and can be confused with greens or browns.
Color Blindness Simulator
Upload an image or screenshot and compare normal vision with common types of color blindness. See the original palette and how it shifts under each simulation.
What color blindness is and why it matters in design
Color blindness (or color vision deficiency) affects the ability to tell certain colors apart, usually reds and greens, though other variants affect different hues. It is not a single condition: there are several types, each with a different pattern of color confusion, and it affects roughly 1 in 12 men and 1 in 200 women.
This has a direct consequence in any project where color communicates something: a combination that looks clearly differentiated to you can look nearly identical to a real part of whoever sees it. A red “error” button on a green background, for example, can be invisible to someone with deuteranopia.
Types of color blindness, explained
Deuteranopia
Absence or reduced sensitivity to green. It is the most common type; reds and greens become hard to tell apart.
Tritanopia
Absence or reduced sensitivity to blue, much less common than the previous two. It affects the distinction between blues and yellows.
Achromatopsia
Total absence of color vision, much rarer. The person perceives the world in grayscale.
How to use the tool
Upload an image from your device or paste a screenshot, then select the vision type you want to simulate (Normal, Protanopia, Deuteranopia, Tritanopia or Achromatopsia). The tool instantly shows how that same image would be perceived, along with the original color palette and the simulated palette, so you can directly compare which colors lose contrast with each other.
Unlike the contrast checker, which measures whether two specific colors meet a minimum readability ratio, this simulator works on a full image, letting you see at a glance whether your design, interface or infographic remains understandable for someone with color blindness, beyond the point contrast between two colors.
Frequently asked questions
It is a condition that makes it harder to tell certain colors apart. The main types are protanopia, deuteranopia, tritanopia and achromatopsia, each with a different pattern of color confusion.
Both affect red–green discrimination, but for different reasons: protanopia reduces sensitivity to red, while deuteranopia reduces sensitivity to green. Visually, the results are similar but not identical.
It affects roughly 1 in 12 men and 1 in 200 women, making it one of the most common visual accessibility conditions to keep in mind.
No. Analysis and simulation run in your own browser, your image is never sent to or stored on any external server.
The contrast checker verifies the readability ratio between two specific colors. This simulator lets you see a full image or design as someone with color blindness would perceive it, catching comprehension issues that go beyond a single color pair.
You can upload JPG, PNG or WEBP files, or paste a screenshot directly.