Colour Blindness Simulator
Simulate how images and colours appear to people with colour blindness.
See your designs through colour blind eyes
Upload an image or enter colours to instantly see how they appear to people with different types of colour blindness. Essential for accessible design.
Drag and drop an image here, or click to select
Supports PNG, JPG, GIF, WebP
How the Colour Blindness Simulator Works
Upload or Enter
Upload an image or enter up to 6 colours
Select Type
Choose which type of colour blindness to simulate
Compare
See instant side-by-side comparison with the original
Download
Download the simulated version to share or reference
The tool uses scientifically-validated colour transformation algorithms to accurately simulate how images appear to people with various types of colour vision deficiency.
Why Use a Colour Blindness Simulator?
Approximately 8% of men and 0.5% of women have some form of colour vision deficiency. This tool helps designers, developers, and content creators ensure their work is accessible to everyone by simulating how colours appear to people with different types of colour blindness.
Common Use Cases
- Web accessibility: Test website colour schemes for WCAG compliance
- UI/UX design: Ensure buttons and links are distinguishable for all users
- Data visualization: Verify charts and graphs are readable by colour-blind users
- Brand design: Check if brand colours work for people with colour vision deficiency
- Educational materials: Create inclusive learning resources
- Product design: Test packaging and product colours for accessibility
Why This Tool?
- Multiple simulation types: Test for protanopia, deuteranopia, tritanopia, and achromatopsia
- Image upload: Upload any image and see how it appears to colour-blind users
- Colour palette mode: Test individual colours and see all simulations at once
- 100% client-side: Your images never leave your browser—complete privacy
- Free to use: No signup required for basic functionality
Frequently Asked Questions
What is colour blindness?
Colour blindness (colour vision deficiency) affects how people perceive colours. The most common types are red-green colour blindness (protanopia and deuteranopia), affecting about 8% of men. Blue-yellow blindness (tritanopia) and complete colour blindness (achromatopsia) are rarer.
What is protanopia?
Protanopia is a type of red-green colour blindness where the eye's red cone cells don't work properly. People with protanopia have difficulty distinguishing between red and green colours. It affects approximately 1% of men.
What is deuteranopia?
Deuteranopia is the most common type of colour blindness, affecting the eye's green cone cells. People with deuteranopia confuse greens, reds, and yellows. It affects approximately 1% of men and is much rarer in women.
How do I design for colour blind users?
Don't rely on colour alone to convey information. Use patterns, labels, or icons alongside colours. Ensure sufficient contrast between adjacent colours. Test your designs with a colour blindness simulator. Avoid red-green colour combinations for critical information.
What percentage of people are colour blind?
Approximately 8% of men and 0.5% of women have some form of colour blindness. Red-green colour blindness is most common. In a room of 50 people, statistically 2-4 will have some colour vision deficiency.
Pro tip: Use this tool alongside contrast checkers to ensure your designs meet WCAG accessibility guidelines.