Test yourself with the Stroop effect

RED printed in green — say the ink, not the word. A classic attention test in twenty rounds.

Tools used in this guide

The job

Reading is automatic — naming ink color means overriding it. The Stroop effect measures that interference: incongruent rounds (word says one color, ink shows another) are reliably slower and error-prone.

Twenty rounds

A color word appears in colored ink; tap the ink's color. About a quarter of rounds are congruent; the rest conflict. The score shows accuracy and mean response time on correct answers.

Worked example

The word RED in green ink: the fast answer 'red' is wrong — the ink is green. Most people run 700–1,200 ms on conflicts and get caught once or twice per twenty.

Where it stops

Device latency is baked into the times — compare yourself across sessions on the same hardware, not to lab norms. It's a demonstration of the effect, not a cognitive assessment.