Color Blindness Test — Free Online Red-Green Ishihara Test
Free online color blind test with live Ishihara plates — quick, standard and kids modes, plus a CVD color blindness simulator. Runs fully in your browser.
Choose a Test Mode
Calibrate first: brightness 100% · Night Shift off · face the screen · no tinted glasses
What number do you see?
Answer within 3 seconds on first glance; if you cannot tell, choose "Cannot see it"
Test Complete
Plate Review
Online tests are affected by screen brightness, color temperature and environment — this is a preliminary self-check only. For physicals, driving licenses or job assessments, rely on a professional eye exam.
Color Blindness Simulator
Switch types to see the same plate under different color vision — a first-person look for normal-vision users
Normal color vision
The orange-red digit and the yellow-green-olive background differ clearly in hue — readable at a glance.
Top: original spectrum · bottom: the same colors seen by this type
About this tool
Do you see the number in the dots? This free color blind test uses Ishihara-style plates generated live in your browser — quick screening in about 40 seconds, a standard 10-plate test, and a shape-based version for kids who can't read digits yet. Everything runs locally: no account, no upload, and every plate is randomly regenerated so you can retake the test as often as you like without memorizing answers.
How the Ishihara test works
Each plate is a field of colored dots. The digit (or shape) is drawn in one family of colors — orange-red tones — while the background uses yellow-green olive tones. The two families are matched for brightness and differ only in hue:
- People with normal color vision separate the families instantly by their red-vs-green hue difference, so the digit pops out.
- People with red-green color blindness (protan or deutan) see both families collapse toward similar muddy tones — the digit blurs into the background.
The first plate in every run is a demonstration plate: its digit is drawn in blue-gray vs tan, which doesn't rely on red-green discrimination at all. Everyone should read it. If you can't, the issue is probably your screen settings, not your color vision — fix that before judging the rest of the run.
Reading your result
The result is a ratio of correctly read plates, reported in three bands:
| Correct | Reading | What it means |
|---|---|---|
| 85%+ | Normal red-green response | You read all or nearly all plates |
| 60–84% | Partial — retest advised | Misses may come from screen glare, rushing, or a mild deficiency |
| Below 60% | Red-green difference likely | Multiple plates unreadable — a professional exam is worth doing |
An online test is a screening hint, not a diagnosis. Screen brightness, color temperature and Night Shift modes all shift the colors. For anything official — a medical exam, a driver's license, a job requirement — the answer that counts comes from an eye-care professional using standardized printed plates or an anomaloscope.
Why the plates look different every time
Classic Ishihara books are printed in fixed ink colors, so answers can be memorized. Here each plate is synthesized on the fly: the dot positions, sizes and exact colors are randomized within each color family on every run. The principle each plate tests stays constant — only the pixel pattern changes. Retaking the test gives a fresh set, which makes practicing for (or gaming) a color vision exam effectively impossible on this page — and makes retakes honest.
The three types of red-green color blindness
Color vision comes from three cone cell types (L / M / S). Red-green deficiency is an X-linked recessive trait, which is why it affects about 1 in 12 men but only about 1 in 200 women.
- Protan (protanopia / protanomaly) — the L (long-wave) cones are missing or shifted. Reds look darker; red vs green is hard to separate. About 1% of men.
- Deutan (deuteranopia / deuteranomaly) — the M (medium-wave) cones. The most common form; roughly 5–6% of men. Overall brightness stays normal.
- Tritan (tritanopia / tritanomaly) — the S (short-wave) cones, causing blue-yellow confusion. Very rare (~0.01%) and not detected by Ishihara plates, which target the red-green axis. Try the simulator below the test to see how each type perceives the plates.
- Monochromacy — no (or minimal) cone function; the world in brightness only. Extremely rare, usually with light sensitivity.
"Color blind" (anopia — the cone is absent) vs "color weak" (anomaly — the cone is shifted) is a matter of degree: mild anomalous trichromats often get through daily life unaware and only discover it at a physical exam. If your work is color-critical, pair this screening with the color codes tool when picking accessible palettes.
Which jobs require normal color vision?
Standard color vision screening is part of the physical exam for roles where misreading a color signal matters:
- Transport: driver's licenses (in many jurisdictions, commercial/professional ones strictly), pilots, railway and maritime crews
- Safety services: police, firefighters, military (varies by branch and role)
- Medicine & lab: clinical medicine, pathology, pharmacy, chemical and lab analysis
- Skilled trades: electrical wiring, aviation maintenance, printing and paint matching, gemology
- Design-adjacent: some fine-arts programs screen applicants at admission
Rules differ by country and by role — check the specific requirement before applying. If you plan to pursue one of these and this test hints at a deficiency, get a professional exam first rather than finding out at the physical. See more free online tools for other browser-based utilities.
FAQ
How accurate is an online color blind test?
As a screening direction, quite indicative; as a measurement, limited. Screen brightness, color temperature, ambient light and viewing angle all shift the colors, and no browser test can match calibrated printed plates under controlled lighting. Use it to decide whether a professional exam is worth booking — not as a final verdict.
What age can kids take it?
Around 3–4 years old with the shape version (circle, square, triangle, star — no digit recognition needed), and 5–6+ once they reliably read digits. Keep it playful and short; a tired or uncooperative child produces noise, not signal. Pediatric vision screening typically uses picture-based plates for the same reason.
Can I pass a driver's license medical with red-green color blindness?
In most places, yes for a private license — ordinary road signals also differ in position and brightness, not just hue, so red-green deficient drivers usually manage. Commercial, bus, pilot and railway licenses are far stricter, and several countries restrict them outright. Check your local regulation; don't rely on a web test either way.
Someone in my family is color blind — will my child be?
It follows X-linked recessive inheritance: a color-blind father passes the gene to all his daughters (carriers, usually not color blind) and none of his sons; each son of a carrier mother has a 50% chance. This is why it clusters in boys through the maternal line.
The plate numbers look faint on my screen — is the test broken?
Check brightness (set 100%), Night Shift / eye-comfort warm modes (turn off), dark-mode browser filters (turn off) and viewing angle (look straight on, 50–70 cm). A cheap or badly calibrated display can wash out the hue difference the test depends on. The demonstration plate is your canary: if that one is hard to read, fix the screen before trusting any result.