Colour blindness test
Twelve dot plates and a colour-matching game — a quick screening, not a diagnosis.
You’ll see 12 circles of coloured dots. Type the number you see in each one, or choose “I can’t see a number”. Sit at a normal distance, with the screen at full brightness.
Screen brightness, night mode or blue-light filters, screen calibration and room lighting all change the colours you see, and so the result.
Nothing leaves your device
This tool runs entirely in your browser. What you type, play or record here stays on your device: nothing is uploaded or saved on a server.
Example
Brown or green? Reading a 7 of 12 result that leans green-weak (deutan)
He and his partner keep arguing about whether a jumper is brown or green, so he takes the dot plate test with the screen at full brightness and night mode off. The 12 plates are 2 controls (the first and the last), 8 red–green plates and 2 blue–yellow plates. The numbers change each time you press Start.
- He reads both control plates, so the result counts. Had he missed one, it would say “Inconclusive” and ask him to check the screen and lighting.
- Plates 3, 7 and 10 — the three green-weak (deutan) plates, 10 a harder one — show him only dots, so he picks “I can’t see a number”.
- Plates 6 and 11 hide two digits, such as 49. He sees only the left one, 4: the right digit vanishes for the green-weak type, so these count towards deutan.
| Answers | Score | Result shown |
|---|---|---|
| All 12 plates read | 12 of 12 correct | No sign of a colour vision deficiency |
| Only the two harder red–green plates (8 and 10) missed | 10 of 12 | No sign of a colour vision deficiency |
| Plates 3, 7 and 10 missed, only the left digit read on 6 and 11 | 7 of 12 | Possible red–green colour vision deficiency, leaning green-weak (deutan) |
| One blue–yellow plate (4 or 9) missed | 11 of 12 | No sign of a colour vision deficiency |
| Both blue–yellow plates missed | 10 of 12 | Possible blue–yellow colour vision deficiency |
| Plate 1 or 12 (a control) missed | 11 of 12 | Inconclusive |
His screen shows “Possible red–green colour vision deficiency” and “Your answers lean towards the green-weak type (deutan).”, 7 of 12 correct: control plates 2 / 2, red–green 3 / 8, blue–yellow 2 / 2. It is a screening, not a diagnosis; an optometrist or eye doctor can test it properly.
How it works
- Turn the screen brightness up, switch off night mode or blue-light filters, and press Start.
- Type the number you see in each of the 12 dot plates, or choose “I can’t see a number”.
- Read the result and review each plate; try the odd-tile game to see how small a colour difference you notice.
Frequently asked questions
- How does the dot plate test work?
- Each plate hides a number in dots whose colours differ only in a way that a particular colour vision deficiency can’t see, while the brightness of the dots is mixed so it gives no clue. People with typical colour vision read the number; people with that deficiency see only dots. The plates are generated by this page.
- What do red–green and blue–yellow mean?
- Red–green deficiencies are by far the most common — about 1 in 12 men and 1 in 200 women — and come in a red-weak (protan) and a green-weak (deutan) type. Blue–yellow (tritan) deficiencies are rare.
- Can a screen test diagnose colour blindness?
- No. Screens differ in colour, and filters and lighting change what you see, so treat the result as a hint. An optometrist or eye doctor can test colour vision properly with calibrated tests.
- What is the odd-tile game for?
- It shows how small a colour difference you notice, and which direction — red–green, blue–yellow or lightness — gave you the most trouble. It is a fun check and a good way to compare screens.
- How many plates do I need to get right?
- Both control plates, the first and the last, or the result is “Inconclusive”. Missing three or more of the eight red–green plates gives “Possible red–green colour vision deficiency”, and missing both blue–yellow plates gives “Possible blue–yellow”. Two red–green misses, such as the two harder plates, still count as no sign of a deficiency.
- Why do some plates have two digits?
- Plates 6 and 11 sort the two red–green types: the left digit vanishes for the red-weak type (protan), the right one for the green-weak type (deutan). Which digit you read, together with which single plates you missed, decides whether the result leans protan or deutan.
- Is anything sent anywhere?
- No. The test runs in your browser and your best score stays on this device.