Stroop test online

How to play the Stroop test

1. Choose how many words per round. 12 words suit younger children, 20 is the standard length here, and 30 is a longer challenge.
2. Round 1: the colors match. The word RED appears in red, the word BLUE in blue, and so on. Tap the button for the color of the ink as fast as you can without mistakes.
3. Round 2: the colors don’t match. Now the word RED might appear in blue or green. Tap the color of the ink, not the word you read. This is the hard part.
4. Look at the results. You will see the time and mistakes for each round and the difference between them. A wrong tap counts as a mistake, and the game moves on to the next word.

On a computer, you can also use the keys R, B, G and Y, or 1 to 4.

What is the Stroop effect?

The test is named after the American psychologist John Ridley Stroop, who described it in 1935 in the Journal of Experimental Psychology. In his experiments, college students read lists of color words aloud. Reading words printed in mismatched ink took only about 2.3 seconds longer per 100 words than reading the same words in black ink. Naming the ink colors of mismatched words was a different story: it took on average 47 seconds longer per 100 items than naming the colors of plain squares, about 74% longer.

A common explanation is that for anyone who reads well, reading a word is so practiced that it happens on its own. When the job is to name the color, the word gets read anyway and gets in the way. Psychologists call this interference. Stroop tasks have been used in research and in neuropsychological testing for decades, mainly as a measure of how well a person can hold back an automatic response and keep attention on the task.

What this version shows

The difference between round 2 and round 1 is your child’s own Stroop effect for that game: how much the mismatched words slowed them down, and whether they made more mistakes. Most children (and adults) are slower in round 2. A big difference is normal and doesn’t mean anything is wrong.

Honest limits

It is a game, not a clinical test. Psychologists use standard versions with set materials, instructions and norms. In Stroop’s experiments, people said the colors aloud; here your child taps buttons, and the rounds are shorter. So the times on this page can’t be compared with published results.

It needs reading. The words only get in the way if your child reads them easily. A child who is just learning to read may show little difference between the rounds. In classic studies, interference was largest in the early school years and became smaller with age, although not every study finds this pattern. Wait until your child reads color words without effort.

It needs color vision. If your child finds it hard to tell some colors apart, for example because of color blindness, this test isn’t a fair one for them.

Practice makes this task faster. In Stroop’s own third experiment, eight days of practice made students much quicker at naming the ink colors of mismatched words, although the interference did not disappear. Large reviews of brain training find that people mostly get better at the task they practice, with little evidence that the gains carry over to other skills. A smaller difference after a week of practice means your child has become better at this game, not that their attention in class has changed.

Common questions

What is a good Stroop test score for a child?

There are no norms for this home version, and the published norms belong to standard clinical versions. Compare your child only with themselves: play the same number of words per round on a few different days and look at the trend. The tool shows the difference from your last game with the same settings.

Is the Stroop test a test for ADHD?

No. This game can’t tell you whether your child has ADHD or any other condition. Psychologists may use a standard Stroop test as one small part of a full assessment, together with interviews, questionnaires and other tests. If you are worried about your child’s attention, talk to your child’s doctor or teacher.

Why is round 2 so hard?

Because the word and the color point to two different answers at once. Saying “blue” when you see the word GREEN in blue ink means holding back the answer that reading offers automatically.

Can adults play too?

Yes. Playing together can be fun: compare who has the smaller difference between the rounds, not who is faster overall.

Sources

• Stroop, J. R. (1935). Studies of interference in serial verbal reactions. Journal of Experimental Psychology, 18(6), 643–662 (full text at Classics in the History of Psychology, York University)
• MacLeod, C. M. (1991). Half a century of research on the Stroop effect: An integrative review. Psychological Bulletin, 109(2), 163–203 (PDF)
• Scarpina, F. & Tagini, S. (2017). The Stroop Color and Word Test. Frontiers in Psychology, 8, 557
• Ruhl, C. Stroop Effect. Simply Psychology
• Arsalidou, M., Agostino, A., Maxwell, S. & Taylor, M. J. (2013). “I Can Read These Colors”: Orthographic manipulations and the development of the color-word Stroop. Frontiers in Psychology, 3, 594
• Lemercier, C., Simoës-Perlant, A., Schmidt, J. R. & Boujon, C. (2017). Stroop interference and development: Influence of expectation on color-naming response times. European Review of Applied Psychology, 67, 43–50
• Simons, D. J. et al. (2016). Do “brain-training” programs work? Psychological Science in the Public Interest, 17(3), 103–186
• Kassai, R., Futo, J., Demetrovics, Z. & Takacs, Z. K. (2019). A meta-analysis of the experimental evidence on the near- and far-transfer effects among children’s executive function skills. Psychological Bulletin, 145(2), 165–188
• Sala, G. & Gobet, F. (2019). Cognitive training does not enhance general cognition. Trends in Cognitive Sciences, 23(1), 9–20