Color blind test
Two short parts, about three minutes. First read numbers hidden in dots, then find the gap in a ring. You get your likely type of color vision and can turn on a color blind mode for this site.
Before you start: use normal room light, turn screen brightness up and switch off night mode, True Tone or blue-light filters.
Part 1 of 2: which number do you see?
Part 2 of 2: where is the gap in the ring?
You can also use the arrow keys, and the space bar for “I can't see the ring”.
Your result
How much difference you needed on each axis (ΔE2000, lower is better)
Typical is up to about ΔE 6 on this test.
How the test works
Part 1 uses number plates made for this site: dots of random lightness, with the number and the background split along one confusion line, so only that type of color vision loses it. Part 2 follows the Cambridge Colour Test method (Regan, Reffin and Mollon 1994): a ring with a gap, made of dots, whose color difference shrinks after each right answer and grows after each wrong one, separately on the protan, deutan and tritan lines. “I can't see the ring” is not counted as wrong: it moves the next ring by the expected step of a guess among four gaps (Kaernbach 2001), so the test never forces a guess. The plates are generated in your browser; the original Ishihara plates are not used.