Color Blindness Simulator

See the world through different eyes. Ensure your images, websites, and designs are accessible to users with color vision deficiency.

Color Blindness Simulator

Upload an image to see how it might appear to someone with a color vision deficiency.

What is Color Vision Deficiency?

Color Vision Deficiency (CVD), commonly known as color blindness, is not a form of blindness at all, but rather a deficiency in the way one sees color. People with CVD can see colors, but they have difficulty differentiating between certain shades of colors. This condition affects millions of people worldwide—approximately 1 in 12 men and 1 in 200 women.

The human eye perceives color through specialized cells called cones. There are three types of cones, each sensitive to different wavelengths of light: red (L-cones), green (M-cones), and blue (S-cones). When one or more of these cone types are absent or not functioning correctly, a person's color perception is altered. Our WCAG Contrast Checker is another essential tool for ensuring your text is readable against its background, a common issue for people with CVD.

The Main Types of Color Blindness

Our simulator allows you to experience the four most common types of color vision deficiency:

  • Protanopia (Red-Blind): This is a type of red-green color blindness where individuals lack the L-cones (red cones). Reds appear as dark, muted shades of green, and some shades of orange, yellow, and green all appear as yellow.
  • Deuteranopia (Green-Blind): This is the most common form of red-green color blindness. It's caused by a lack of M-cones (green cones). Like Protanopia, it causes difficulty in distinguishing between red and green hues.
  • Tritanopia (Blue-Blind): A rarer form of CVD where individuals lack S-cones (blue cones). This makes it difficult to distinguish between blue and green, and between yellow and violet.
  • Achromatopsia (Monochromacy): The rarest and most severe form of color blindness. Individuals with Achromatopsia see the world in shades of gray, black, and white. They have no functioning cone cells.

Why is Simulating Color Blindness Crucial for Design?

When you design a website, application, or marketing material, you intend for your message to be clear to everyone. However, if your design relies heavily on color to convey information, you might be excluding a significant portion of your audience. Important information conveyed only by color—such as red for an error message or green for success—can be completely lost on someone with CVD.

Using a tool like this simulator helps you:

  • Build Empathy: Experience your designs from a different perspective.
  • Identify Accessibility Issues: Quickly spot where your designs fail. Is that chart unreadable? Does that Sale tag blend into the background?
  • Make Informed Decisions: Choose color palettes that are robust and accessible. Our Image to Color Palette Extractor can help you find colors in an image, and this simulator can help you test them.
  • Comply with Standards: Adhering to Web Content Accessibility Guidelines (WCAG) is not just good practice; for many organizations, it's a legal requirement.

How to Use the Color Blindness Simulator

  1. Upload Your Image: Click the "Upload an Image" button and select an image file from your computer. This could be a screenshot of your website, a user interface element, a graph, or any visual you want to test.
  2. View the Simulation: Once uploaded, you will see your original image on the left and the simulated, colorblind-friendly version on the right. By default, the simulation for Protanopia is shown.
  3. Switch Between Types: Use the dropdown menu below the images to switch between the different types of color blindness (Protanopia, Deuteranopia, Tritanopia, and Achromatopsia).
  4. Analyze the Results: Compare the two images. Can you still understand the information in the simulated version? Are there any elements that become confusing or lose their meaning? For example, if you have a form with error fields highlighted in red, do they stand out in the Deuteranopia simulation?

Best Practices for Accessible Color Design

After using the simulator, you might be wondering how to improve your designs. Here are some key principles:

  • Don't Rely on Color Alone: Use multiple visual cues to convey information. Add icons, text labels, patterns, or textures to reinforce meaning. For example, alongside a red error message, add an X icon.
  • Ensure High Contrast: Text, icons, and other important elements should have a strong contrast against their background. This helps everyone, not just those with CVD. Use our Contrast Checker to test your color pairs against WCAG standards.
  • Use Accessible Palettes: When choosing a color scheme, opt for palettes that are known to be distinguishable for people with common forms of CVD. Avoid red/green and blue/yellow combinations for conveying important states.
  • Label Swatches: If you display a range of color options for a product, always include a text label (e.g., Deep Ocean Blue) next to the color swatch.

Frequently Asked Questions

Is this simulation 100% accurate?
This tool provides a close approximation of how someone with a specific type of CVD might see. It uses standard color matrix transformations to simulate the effect. However, the severity of CVD can vary from person to person, so individual experiences may differ.
What image file types can I upload?
You can upload most common image formats, such as JPG, PNG, GIF, and WEBP.
Is my data safe?
Yes. All image processing is done directly in your browser. Your images are never uploaded to our servers, ensuring your privacy.
Can this tool check an entire website?
This tool is designed to check individual images. To check a full website, you can take a screenshot of the page and upload it. There are also browser extensions that can apply color blindness filters to live websites.