Quizzes & Tests
Color Blindness Test
Take a free at-home Ishihara-style red-green color-vision screening with plates drawn fresh in your browser.
Completely FREE Color Blindness Test. No signup, no email, no credit card. Instant results, no catch. Read a short series of dotted color plates, tell us which hidden number you see in each, and get an instant, cautious screening for red-green color vision — entirely in your browser, with nothing installed and nothing saved.
The plates are drawn fresh in your browser every time, so you are never looking at a copyrighted plate from any published test. Each one hides a number in a mosaic of colored dots. If your color vision is typical, the number stands out; if you have a red-green difference, it tends to blend into the background. It takes about three minutes, and there is a control plate along the way to check that your screen and lighting are behaving.
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What this color blindness test actually checks
This is a screening for red-green color vision deficiency — by far the most common type, affecting roughly one in twelve men and about one in two hundred women. It uses the classic dot-plate idea made famous by Dr Shinobu Ishihara: a number is drawn from dots of one color family and hidden inside a background of dots from another color family. The two families are chosen to differ in hue along the red-to-green axis while staying close in brightness, so the number can only be picked out by color, not by lightness.
Because the plates here are generated by code rather than copied, no protected artwork is reproduced. What is shared across all such tests is the underlying method — dot mosaics that isolate hue — and that method is not owned by anyone. Every plate you see is built at random the moment you open the test.
How the hidden-number plates work
Each plate starts with a numeral drawn invisibly onto a small canvas. Every dot that lands inside the shape of that numeral is colored from the figure palette (warm reds and oranges); every dot outside it is colored from the background palette (greens and olives). The trick that makes it a real screen is that both palettes contain a spread of light and dark shades whose brightness overlaps. That removes brightness as a shortcut, so the only thing separating the number from its background is the red-green hue difference — exactly the signal that color vision deficiency affects.
For someone with typical color vision, the reds and greens look clearly different and the number pops out. For someone with a red-green deficiency, those hues look far more alike, so the number softens or disappears into the dots. No single plate proves anything, which is why the test uses several.
How to get an accurate result
Viewing conditions matter more here than in almost any other online test. Use a proper color screen — a phone, tablet, or monitor — at normal brightness, and turn off any night-mode, blue-light, or color filters, because those shift the very hues the test depends on. Avoid direct sunlight on the screen, don't tilt the display (the colors change with angle), and glance at each plate naturally instead of straining to force a number to appear. The control plate is your safety check: if you can't read the number almost everyone can see, your setup is off and the rest of the result can't be trusted.
Reading your result honestly
Your result is deliberately cautious, and it will never name a specific diagnosis. If you read most plates as expected, your responses are simply consistent with typical color vision on this quick check. If you miss several, the result may be suggestive of a red-green difference — but it could equally come from your screen, your lighting, or a few unlucky guesses. An at-home dot test cannot tell those causes apart, cannot diagnose color blindness, cannot rule it out, and cannot identify which type you might have. It is a curiosity tool and a nudge, not an answer.
Frequently asked questions
Is this a real diagnosis? No. It is a screening for fun and learning. Only an eye-care professional using properly calibrated materials can actually assess your color vision. If it matters for a job, for safety, or for your own peace of mind, book a real test.
Why does my screen matter so much? The test works by comparing subtle hues, and screens vary enormously in how they render color. Brightness, contrast settings, night-mode filters, and even the angle you hold the screen at can all make a number easier or harder to see, which is why the same test can give different results on different devices.
Is it really free and private? Completely. There is no sign-up, no email, and no payment. Every plate is generated and scored inside your browser — nothing you click is uploaded, and refreshing the page erases the whole session.
Can I retake it? Yes. Trying again reshuffles the order of the plates and the hidden numbers, so you can't simply memorise answers. As with any screen, treat a first honest attempt under good lighting as the most meaningful one.
What if I fail the control plate? That almost always means a display or lighting problem rather than a color vision issue — brightness too low, a color filter switched on, glare, or a tilted screen. Fix the conditions and run it again before drawing any conclusions.
Important
This is an at-home color-vision screening for curiosity and education only — NOT a medical diagnosis. Screen settings, brightness, and lighting strongly affect the result, and no online test can replace an eye-care professional. If you have any concern about your color vision, see an optometrist or ophthalmologist for a properly administered test.
Support
Problem with this tool or suggestions for improvement? Please email support@niftyutilities.com.