Free Color Blindness Simulator — Test Accessibility
Simulate 8 types of color vision deficiency including Protanopia, Deuteranopia, Tritanopia, and more with side-by-side comparison. Runs entirely in your browser.
How to Use the Color Blindness Simulator
- Select a type — choose from 8 types of color vision deficiency.
- Adjust severity — use the slider to simulate partial or complete color blindness.
- Input colors — paste or pick colors to see how they appear with each condition.
- Upload image — test how photos, charts, or UI designs look to color-blind users.
- Compare — use side-by-side or grid view to compare all 8 types at once.
Why Use This Color Blindness Simulator
Approximately 8% of men and 0.5% of women have some form of color vision deficiency. Ensuring your designs are accessible to everyone is not just ethical — it's often a legal requirement. This simulator helps you identify problematic color combinations before they reach production.
By testing your UI with all 8 types of color blindness, you can ensure that charts, graphs, status indicators, and other color-dependent elements remain distinguishable for all users. The image upload feature lets you test real screenshots and designs.
Frequently Asked Questions
Protanopia/Protanomaly — reduced red sensitivity. Deuteranopia/Deuteranomaly — reduced green sensitivity (most common). Tritanopia/Tritanomaly — reduced blue sensitivity. Achromatopsia/Achromatomaly — complete or partial loss of color vision. "Anopia" means complete absence, "Anomaly" means partial reduction.
The simulation uses color transformation matrices based on scientific research into how different types of color blindness affect perception. While not a perfect replacement for real vision deficiency, it provides a very close approximation useful for design testing.
No. All image processing happens in your browser using the Canvas API. The image is never uploaded to any server and remains only in your browser's memory while the page is open.
Use Cases
Website Accessibility Testing
Test your website for color blind users by simulating how your design appears to people with Protanopia, Deuteranopia, or Tritanopia before going live.
Data Visualization Validation
Validate that color-coded charts, graphs, and data visualizations remain distinguishable for users with color vision deficiencies.
Presentation Contrast Check
Check that your presentation slide colors have enough contrast and remain readable for all audience members with different vision types.
Infographic Readability
Ensure your infographics and information-dense designs are readable by simulating how colorblind users perceive your color choices.
Inclusive UX Audit
Perform a comprehensive UX audit for inclusive design by testing all your UI color combinations against the 8 major color blindness types.