Stroop Color-Word Test
A short practice, then three blocks of 24 trials — 72 scored trials in about 6–8 minutes. Interference and facilitation effects, reaction time and accuracy by condition, inverse efficiency, and variability. Free with a registered account.
The three blocks
Congruent
Color words appear in their own ink color — RED printed in red. Your fastest condition, helped by the automatic reading response. 24 trials, preceded by a short mixed practice with feedback (never scored).
Color naming (XXXX)
Rows of XXXX appear in colored ink. Your pure color-naming baseline, with no word information present at all. 24 trials.
Incongruent (interference)
Name the ink color while ignoring a conflicting color word — RED printed in blue. The classic Stroop conflict. The slowing relative to the congruent and neutral blocks is the Stroop Interference Effect — your executive inhibition score. 24 trials.
Common questions
How long does it take?
About six to eight minutes. You complete a short 8-trial practice with feedback, then three blocks of 24 trials each — 72 scored trials — with brief rest screens in between.
Is it free?
Yes — no payment is required. Taking the Stroop requires a free registered account. Your report shows reaction time and accuracy for each condition, the interference effect measured two ways (incongruent minus congruent, and incongruent minus neutral), the facilitation effect (neutral minus congruent), inverse efficiency scores that correct for speed–accuracy trade-offs, and your reaction-time variability. Everything is reported as your own raw performance — there is no population norm, percentile, or T-score.
How accurate is an online Stroop test?
Browser-based reaction-time tasks are now well-validated for research and self-screening when implemented carefully. Stimulus onset is timestamped on the exact frame painted to your screen and responses use hardware-stamped event timing, so the precision is much closer to lab-grade than to a casual quiz. Any single administration is still a snapshot — sleep, caffeine, and distraction all move the score — so treat it as descriptive of one session, not a fixed trait.
Can I retake it?
Yes. Practice effects on the Stroop are modest but real, so the very first administration tends to be the most diagnostic. If you retake, expect a small speedup across all blocks; the interference effect itself is much more stable.
What's the difference between this and a clinical Stroop?
A clinical Stroop (Golden, 1978; D-KEFS Color-Word Interference) is administered in person by a clinician with stopwatch timing or paper-and-pencil sheets, and is interpreted alongside other neuropsychological tests as part of an evaluation. This online version uses the same paradigm — congruent word-color trials, a neutral color-naming baseline, and incongruent interference trials — but is self-administered, computer-timed, and intended for self-knowledge or research rather than clinical diagnosis.