Name the ink colour, not the word — the classic attention test, timed and free
The Stroop Test asks you to name the colour a word is printed in while ignoring the word itself. John Ridley Stroop published the effect in 1935 and it has been reproduced continuously ever since — reading is so automatic in literate adults that the word interferes even when you know it will. This is the timed version, with your errors and response times recorded.
A colour word appears, printed in a conflicting colour.
Name the ink colour, not the word.
Answer as fast as you can while staying accurate.
Congruent and incongruent trials are mixed.
Your result shows the time difference between the two — the Stroop effect itself.
A round lasts 30, 60 or 90 seconds. Six colours are used, and about 80% of the words are incongruent — the word names a different colour from its ink. Each correct answer scores 10 points; once you have five or more correct in a row, each answer scores 15.
A wrong answer scores nothing and resets the combo, but costs no points. Accuracy is shown at the end, and your best score is saved in this browser. You can answer with the keys 1 to 6 as well as by tapping, which removes aiming time from the measure.
Cognitive inhibition and selective attention — suppressing an automatic process in favour of a controlled one. It is the most widely used single measure of executive control there is. More focus games to try next: Minefield and Odd Shape. Why the colour word slows you down is covered in the Stroop test explained.
J. Ridley Stroop published the effect in 1935: naming the ink colour of a word is much slower when the word names a different colour. Reading is so automatic that the word is processed whether you want it or not, and you have to suppress it to answer.
It is one of the most replicated findings in psychology — a 1991 review already counted hundreds of experiments — and versions of it are used clinically as a measure of inhibitory control. Practice does reduce the interference on the task itself, but, as with most cognitive training, there is little evidence that it transfers to self-control in everyday life.
Blur your eyes slightly so the word is less legible. Degrading the text weakens the automatic reading.
Look at one letter rather than the whole word — a single letter carries the colour without triggering the word.
Say the colour aloud. Committing verbally beats the word to the response.
Slow down a fraction. Nearly all errors come from answering faster than inhibition can act.
The reliable finding that naming the ink colour of a conflicting colour word takes longer, and produces more errors, than naming the colour of a neutral or matching word. Stroop described it in 1935.
Reading is automatic and highly practised; colour naming is not. The word reaches your response system first and has to be suppressed.
It shrinks but does not disappear. That persistence is why the task has remained useful for ninety years.
Standardised versions are used in neuropsychological assessment. A web version is practice, not an assessment, and no score here means anything diagnostically.
The test then measures colour vision rather than inhibition. Go/No-Go measures the same executive function without relying on colour.