18 Ishihara plates. Results in under 2 minutes. No login, no cost, ever. Screen for deuteranopia, protanopia, tritanopia, and achromatopsia.
Simulate protanopia, deuteranopia, tritanopia, and complete achromatopsia with scientifically accurate color shifts.
Upload images, screenshots, or enter a website URL to see instant results — no account required.
Real-time previews powered by advanced rendering ensure your accessibility checks don’t slow you down.
Check if your colors meet the Web Content Accessibility Guidelines for contrast and visibility.
Use our free tools in three steps — whether you’re checking your own vision or testing a design for WCAG accessibility compliance.
Step through 18 color plates. Each shows a number hidden in colored dots — visible differently based on your color vision. Results in under 2 minutes, no sign-up needed.
Start the Free Test →Upload any image or enter a website URL to preview how it looks under protanopia, deuteranopia, tritanopia, or achromatopsia — instantly, in the browser.
Open the Simulator →Identify color-coded elements that fail for CVD users. Adjust your palette and verify contrast ratios meet WCAG 2.2 criteria 1.4.1 and 1.4.3.
Check Your Contrast →Approximately 8% of men and 0.5% of women worldwide have some form of CVD. Each type affects color perception differently — take a dedicated test to identify yours.
Green-Blind
Greens and reds appear as yellows or browns. The most prevalent form of red-green color blindness, affecting roughly 1 in 12 men.
Test for Deuteranopia →Red-Blind
Reds appear very dark or near-black. Common confusion between red, brown, and green. Affects approximately 1% of males.
Test for Protanopia →Blue-Blind
Blues appear greenish and yellows shift toward pink or red. A rare condition affecting roughly 1 in 10,000 people.
Test for Tritanopia →Complete Color Blindness
All colors perceived as shades of grey. Extremely rare (1 in 30,000) and often accompanied by light sensitivity.
Test for Achromatopsia →Approximately 300 million people worldwide have some form of color vision deficiency — roughly 8% of all men. Color accessibility is not optional; it is a legal requirement under WCAG 2.2 (criteria 1.4.1 and 1.4.3) for most digital products.
Suspect you may have CVD? Take the free Ishihara test for a fast, private screening — no sign-up, no download, results in under 2 minutes.
Take the Test →Upload images or enter any website URL to simulate all four CVD types in real time. Catch accessibility issues before they reach production.
Open the Simulator →Verify WCAG 2.2 compliance with the built-in contrast checker. Document CVD simulation results as evidence for accessibility audits and reports.
Check WCAG Contrast →Learn how color vision deficiency impacts hiking, fishing, climbing, and team sports. Real solutions and gear recommendations for outdoor enthusiasts with CVD.
Read Guide →Understand the science behind color blindness, including cone and rod biology, color perception, and why people with CVD see colors differently.
Read Guide →Learn when an online color blind test result means you need to see an optometrist or eye specialist. Signs, next steps, and what to expect from professional CVD testing.
Read Guide →Everything you need to know about color vision deficiency testing and accessibility.
A color blind test — also called a color vision test — is a simple screening that checks whether you can distinguish colors normally or have a color vision deficiency (CVD). The most widely used format is the Ishihara test, which shows numbered plates made of colored dots. People with normal vision read the numbers clearly; those with CVD see a different number or nothing at all.
The four clinically recognized types are: Deuteranopia (green-blind) — the most common form, greens and reds appear as yellows; Protanopia (red-blind) — reds appear very dark or black; Tritanopia (blue-blind) — blues appear greenish, yellows shift pink; and Achromatopsia (complete color blindness) — all colors are perceived as shades of grey.
Approximately 300 million people worldwide have some form of color vision deficiency — roughly 8% of all men. Individuals who suspect they may have CVD can take the free test for a fast, private result. Designers, developers, and accessibility professionals can use the simulator to upload their own images or enter a website URL and preview their work under each CVD condition.
Our test uses Ishihara-style plates based on peer-reviewed research and is highly accurate for screening red-green color blindness. The simulation uses the Machado, Oliveira & Fernandes (2009) color transformation matrices — the same methodology used in professional tools like Adobe Photoshop. For a formal clinical diagnosis, consult an optometrist.
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