What is color blindness?

Color blindness (color vision deficiency) is a condition where people have difficulty distinguishing certain colors. Types include Protanopia/Protanomaly (red-green), Deuteranopia/Deuteranomaly (red-green), and Tritanopia/Tritanomaly (blue-yellow). Approximately 8% of men and 0.5% of women have some form of color vision deficiency.

Why should I test images for color blindness?

Testing images for color blindness ensures your designs are accessible to all users. Accessible designs improve user experience for everyone and help you comply with WCAG accessibility guidelines. This tool helps you identify potential issues before deployment.

What types of color blindness can I simulate?

Six types: Protanopia (severe red-green, cannot see red), Protanomaly (mild red-green), Deuteranopia (severe red-green, cannot see green), Deuteranomaly (mild red-green, most common), Tritanopia (severe blue-yellow), and Tritanomaly (mild blue-yellow). You can view them individually, side-by-side with the original, or all at once.

How do I use the color blindness simulator?

Upload your image (drag & drop, file picker, or paste URL), choose a view mode (single, side-by-side, or all types), select color blindness types to compare, and review the simulations. Download any result to share with your team.

What should I look for when testing?

Check if important information relies solely on color. Ensure text is readable, buttons are distinguishable, error states are clear, and information is conveyed through shapes, patterns, icons, or text labels in addition to color. Test critical user flows like forms and alerts.

Is the color blindness simulator free?

Yes, completely free! No registration, no limits, no hidden fees. All image processing happens in your browser - we never see or store your images. Your privacy is protected.

Can I load images from URLs?

Yes! You can paste an image URL in the URL input field and click 'Load from URL'. Note that some images may be blocked by CORS policies, in which case you should download and upload the image directly.

👁️ Color Blindness Simulator

Simulate color blindness to test image accessibility. Preview how images look with different types of color vision deficiency.

View Mode

Color Blindness Type

Full color vision with all three types of cones functioning normally. (Most of the population)

Upload Image

Click to upload or drag and drop

image/*

Max size: 10.00 MB

Or load from URL

About Color Blindness

Protanopia/Protanomaly: Red-green color blindness affecting red cone sensitivity. Protanopia (severe) affects ~1% of males, Protanomaly (mild) affects ~1% of males.

Deuteranopia/Deuteranomaly: Red-green color blindness affecting green cone sensitivity. Deuteranopia (severe) affects ~1% of males, Deuteranomaly (mild, most common) affects ~5% of males.

Tritanopia/Tritanomaly: Blue-yellow color blindness affecting blue cone sensitivity. Very rare, affects ~0.01% of population.

Use this tool to test your designs for accessibility and ensure information is conveyed through more than just color. Test critical user flows and ensure sufficient contrast.

How to Simulate Color Blindness

Upload a screenshot, UI mockup, or illustration (drag & drop, file picker, or paste URL).
Choose a view mode: Single (one type), Side-by-Side (compare with original), or All Types (grid view).
Select color vision deficiency types: Protanopia/Protanomaly, Deuteranopia/Deuteranomaly, or Tritanopia/Tritanomaly.
Review the preview to see how users with each condition perceive your design.
Download any simulation result to share with teammates or attach to QA reports.

Tip: Use "All Types" view to quickly compare all simulations. Test critical flows (forms, buttons, alerts) to ensure color alone isn’t conveying important information.

Color Blindness Types Explained

Protanopia (Severe)

Red cones missing

Reds look darker and blend with greens. Affects ~1% of males, ~0.01% of females.

Protanomaly (Mild)

Reduced red sensitivity

Milder form of red-green color blindness. Affects ~1% of males.

Deuteranopia (Severe)

Green cones missing

Greens fade toward beige. Affects ~1% of males, ~0.01% of females.

Deuteranomaly (Mild)

Reduced green sensitivity

Most common form of color blindness. Affects ~5% of males.

Tritanopia (Severe)

Blue cones missing

Blues and yellows shift dramatically. Very rare, affects ~0.01% of population.

Tritanomaly (Mild)

Reduced blue sensitivity

Milder form of blue-yellow color blindness. Very rare, affects ~0.01% of population.

Accessibility Best Practices

Use redundant cues: combine color with icons, labels, or patterns.
Maintain sufficient contrast (WCAG AA) so text remains legible for most users.
Avoid pairing problematic colors (red/green, blue/yellow) for status indicators.
Document findings and share the simulated previews during design critiques.