Free Stroop Test
Name the ink color of 30 color words as fast as you can. See your accuracy, reaction time and the Stroop effect between matching and mismatched words.
Loading tool…
How to take the Stroop test
The Stroop test shows how hard it is to ignore something your brain does automatically: reading. When the word RED is printed in blue ink, naming the ink takes longer than when the word and the ink match. That extra time is called the Stroop effect.
- Press Start. A plus sign appears, then a color word.
- Ignore what the word says. Choose the color of the ink with the buttons or the keys 1 to 4.
- Answer all 30 words as quickly as you can without guessing.
- Half the words match their ink and half do not; the order is random.
- Read your accuracy, average time and the difference between matching and mismatched words.
How the Stroop test is scored
Each word appears after a short fixation sign, and your time is measured from the moment the word is drawn until you answer. Only correct answers count toward the average times. The Stroop effect is the average time on mismatched words minus the average time on matching words.
On the Spanish page the words appear in Spanish, so the test always uses the language you read most easily.
What's a good Stroop test result?
A small effect with high accuracy is the best combination. As a rough guide for this browser version:
| Stroop effect | Rating |
|---|---|
| Under 50 ms | Excellent focus |
| 50–120 ms | Typical |
| 120–200 ms | Noticeable interference |
| Over 200 ms | Strong interference |
Useful tips and limitations
- Blur your focus slightly and look at the color of the letters rather than their shape.
- Keep your fingers on the 1 to 4 keys, or your thumb in the middle of the buttons on a phone.
- Aim for at least 90% accuracy; a tiny Stroop effect from guessing is not a real result.
Common questions
What is the Stroop effect?
It is the slowdown when a color word and its ink color do not match. Reading happens automatically, so your brain has to override the word before it can name the ink.
Is a smaller Stroop effect better?
Generally yes: it means you are good at ignoring distractions. Accuracy matters too, so check that you were not simply guessing quickly.
Why is it harder when the word and color do not match?
Two processes compete: automatic reading and deliberate color naming. Resolving that conflict takes extra time.
Does the Stroop test work on a phone?
Yes. Use the four large color buttons. Phone screens and touch input add a little delay, so compare phone results with phone results.
Every test runs in your browser. Answers, scores and streaks are saved only in this browser on this device; nothing is uploaded and no account is needed. Clearing site data removes your saved scores.