Stroop Test Online — Color-Word Interference Challenge
The classic psychology attention task, playable in your browser: a color word appears in a mismatched ink color — answer the ink, not the word. 45 seconds per round, instant reaction-time stats, and a rule-switch mode you will not find elsewhere. Scores never leave your device.
Always answer the INK color. Tap a color button, or press 1–4 / R G B Y
Pick a mode, press start, and answer as fast as you can for 45 seconds.
Finish a round to start your local history.
How to read your scores — published anchors: interference ≈72 ms and 106.3 ms, reaction time 589.6/661.2 ms. Full scoring standards →
How this Stroop test works
Each round shows one word at a time for 45 seconds. The word names a color, but the ink may be different — your job is to answer the ink color (or, in Rule-switch mode, the word meaning whenever the cue frame appears). About half the trials are congruent (word matches ink) and half incongruent, so the test constantly pits the automatic habit of reading against the required response.
After the round you get four numbers: correct answers, errors, average reaction time in milliseconds, and your interference cost — how much slower incongruent trials were than congruent ones. That last number is your personal Stroop effect. For published reference values with sources, see the Stroop effect standard scores page; for offline practice, the printable color-word cards.
A honest note on what training here does: practice reliably makes you faster at this task (near transfer), and the trend is visible in your local history. Claims that any brain game raises general intelligence go beyond the evidence — treat this stroop test online as a focused, measurable attention drill, not an IQ booster or a medical assessment.
How to take the test
- Pick Classic mode (always answer the ink color) or Rule-switch mode (a boxed word means: answer the word meaning instead).
- Press Start. A color word appears — tap the matching color button, or press keys 1–4 / R G B Y.
- Keep going for 45 seconds: half the words match their ink, half conflict. Wrong answers flash red and count as errors.
- Read your score: correct answers, errors, average reaction time and interference cost. Results are stored locally so you can track your trend.
What your results mean
| Metric | What it tells you |
|---|---|
| Correct answers | How many trials you answered correctly in 45 seconds — your throughput under interference. |
| Errors | How often the automatic word-reading response won; most people slip a few times on incongruent trials. |
| Average reaction time | Mean speed of your correct answers, in milliseconds. |
| Interference cost | Average reaction time on incongruent minus congruent trials — the Stroop effect in your own data. |
No universal pass/fail score exists for a 45-second button-press round. Published values for the interference cost, age and practice effects — each with its source — are collected on the Stroop effect standard scores page.
Printable Stroop cards
Prefer paper? Generate fresh randomized color-word cards for offline practice — every sheet is newly randomized. Open the printable Stroop cards →
Frequently asked questions
What is the Stroop test?
The Stroop test is a classic attention task from experimental psychology: you see a color word (like “RED”) printed in a mismatched ink color, and you must name the ink, not read the word. The delay caused by the conflicting word — the Stroop effect — measures selective attention and response inhibition. It has been used in research since 1935.
How does the Stroop test work?
Each round shows one word at a time for 45 seconds. Tap the button matching the ink color — or press 1–4 / R G B Y — as fast as you can. Half the words match their ink (congruent), half conflict (incongruent). The test scores your correct answers, errors, average reaction time, and the interference cost: incongruent minus congruent response time.
What does the Stroop test measure?
It measures selective attention — focusing on one property (ink color) while suppressing an automatic response (reading) — plus processing speed and response inhibition. These are real, trainable skills, but this online version is not a diagnosis: clinicians use longer, normed versions as one small piece of a larger assessment.
What is a good score on the Stroop test?
There is no universal pass/fail score. On button-press versions like ours, published studies find incongruent trials run roughly 70–110 ms slower than congruent ones in healthy adults; an interference cost in that range is typical. Count your correct answers in 45 seconds and compare against your own history — your trend matters more than any single number.
Is the Stroop test an IQ test?
No. It probes one specific skill — resolving conflict between an automatic and a required response — not general intelligence. Practicing the game mainly makes you better at the game (near transfer), and there is no solid evidence it raises IQ. Treat it as a focused attention drill with a measurable trend, not a brain score or medical test.