Stroop color-word test

Read the word. Answer with the ink.

By Cristian Dominguez Rein-Loring, Creative Technology Lead · Published September 5, 2026

The Stroop task creates conflict between a word you can read automatically and the ink color you need to report. The added difficulty in the conflict condition is called Stroop interference.

Start the Stroop task See how it works

3 timed conditionsAbout 4 minutesInformational only

Name the ink, not the word

BLUECorrect response: red

Automatic signalRead “blue”

Task goalReport red ink

ConflictCompeting information

What it measures

A sample of interference control, not a verdict

People usually name an ink color more slowly or less accurately when a color word names a different color. The Stroop effect is the change between that conflicting condition and an appropriate baseline. It is commonly used to study selective attention, competing responses, and cognitive control.

Calling Stroop a pure “inhibition test” is too simple. Performance also depends on basic reading and color-naming speed, language and literacy, response mapping, attention, vision, and motor speed. Researchers use several task versions and several ways to calculate interference.

One Stroop result is one performance sample. It cannot diagnose ADHD, dementia, brain injury, or any other condition. A qualified assessment considers history, daily functioning, multiple measures, and appropriately matched norms.

This browser version

Three conditions separate baseline speed from conflict

Word reading. Read RED, GREEN, or BLUE in black and choose the matching word. Five practice trials come before the 45-second block.
Color naming. See colored XXXX marks and choose their ink color. This also has five practice trials and a 45-second block.
Interference. Choose the ink color when the word names a different color. After practice, answer as many as you can in 45 seconds.

The result keeps the baselines visible. It reports correct responses, errors, and response times by condition, then derives interference comparisons from the word-reading, color-naming, and conflict blocks. A derived score is withheld when there are not enough valid baseline responses.

Before you start

Give the task a fair testing setup

For a cleaner attempt

Use a quiet setting and avoid switching tabs during timed blocks.
Make sure you can distinguish the red, green, and blue stimuli.
Use the response method you can operate consistently: keys or on-screen buttons.

Interpret cautiously when

Reading fluency or the test language adds difficulty.
Color vision, low vision, motor access, or assistive input affects responding.
You are tired, stressed, distracted, medicated, or repeating the task after practice.

Browser administration is not identical to a clinical test. Screen, keyboard, touch input, browser timing, and the exact Stroop format can change scores. Do not compare a result directly with norms from a different version unless the method supports that comparison.

Evidence

The task and its interpretation

Stroop (1935): Studies of interference in serial verbal reactions, the original color-word experiments.
MacLeod (1991): Half a century of research on the Stroop effect, an integrative review of the evidence and competing explanations.
Scarpina and Tagini (2017): The Stroop Color and Word Test, a review of versions, scoring, and normative interpretation.
Peña-Casanova et al. (2009): NEURONORMA Spanish Stroop norms, showing the importance of sample, age, and education in clinical norming.

Ready for the full three-condition task?

Set aside about four uninterrupted minutes. The runner includes practice before each timed condition and shows the baselines used for its interference comparison.

Start the Stroop task