Stroop test
Name the color of the ink, not the word. See how much a mismatched word slows you down, in milliseconds.
- 1A color word appears in colored ink: for example, BLUE printed in red.
- 2Answer with the color of the ink, not the word, as fast as you can. Tap a button or press 1 to 4.
- 3Four practice trials come first. Then 40 trials count: half where the word and ink match, half where they don’t.
4 practice + 40 trials · nothing is saved
How scoring works
- Your result is the Stroop effect: how much longer, on average, you take to answer mismatched words than matching ones.
- Only correct answers count toward the averages. Each answer is timed from the moment the word reaches your screen.
- No answer within 3 seconds counts as too slow. Your accuracy is shown alongside your times.
- Matching and mismatched trials are mixed in random order, and the ink never repeats from one trial to the next.
A little perspective
If some colors are hard for you to tell apart, especially red and green, the result won’t reflect the Stroop effect fairly. This practice version is not a clinical assessment.
Results describe your performance on this task, with no invented percentiles or IQ equivalents.
What is the Stroop test?
In the Stroop test, color words are printed in colored ink, and you name the ink rather than read the word. When the word and the ink match, like RED in red, answering is easy. When they don’t, like RED in blue, the word you read automatically competes with the color you need to name, and most people slow down. That slowdown is the Stroop effect, first described by John Ridley Stroop in 1935.
This online version mixes 40 matching and mismatched trials after a short practice. It times each correct answer from the moment the word reaches your screen and reports the difference between the two kinds of trial in milliseconds. The words appear in the language of this page, because the effect depends on reading a language you know well.
Getting started
- Rest your fingers on the answers, or use the keys 1 to 4, so your time goes into deciding rather than reaching.
- Look at the color as a whole patch rather than reading the letters.
- Speed and accuracy trade off against each other. Compare runs where your accuracy was similar.
Read how Logitally tests and scores work for more about interpreting results.
Common questions
What does the Stroop test measure?
It shows how much an automatic habit, reading, gets in the way of a deliberate task, naming a color. The size of the slowdown is often described as a measure of interference control. Here it describes your performance on this task, not a diagnosis.
What is a normal Stroop effect?
Most people answer mismatched words more slowly, but by how much varies with the version of the test, the device and practice. This site does not assign norms or percentiles, so compare your own runs instead.
Can I take the Stroop test if I’m color blind?
You can try it, but if some of the four colors are hard for you to tell apart, especially red and green, slower answers may come from telling the colors apart rather than from the Stroop effect. The result would not be a fair measure.