What counts as a good result?

High accuracy with a steady speed is the goal. Most people are noticeably slower on the mismatched words than the matching ones, and a smaller gap between the two suggests stronger attention control. Compare your own runs rather than chasing a fixed target.

Is this a medical or diagnostic test?

No. It is a fun, informational version of a well-known attention task. It is not a clinical assessment and should not be used to diagnose anything.

Are my best scores saved?

Your best result for each game is kept in your browser so you have something to beat next time. It lives only on this device, so clearing your browser data or switching to another device starts you fresh. Nothing is tied to an account because there is no account.

Does anything I do here get sent to a server?

No. Every game runs locally in your browser. Your scores and any text you type stay on your own device, nothing is uploaded, and nothing is logged or stored by us. Once the page has loaded it keeps working even if you go offline.

Stroop Test

A colour word appears, printed in a colour that often does not match. Your job is to name the ink colour, not read the word. This free Stroop test measures how well you push past conflicting information, reporting your reaction time and accuracy. It is a classic attention exercise, run entirely in your browser with no sign-up.

No sign-up, ever
100% free
Nothing uploaded
Works offline after first load
Scores stay on your device

Read the guide: What Is the Stroop Effect?

20 wordsBest avg: —

Name the ink colourPick the colour the word is printed in — not the word itself. 20 quick rounds.

How to use it

1
Read the rule

You answer with the colour the word is printed in, ignoring what the word says.
2
Answer quickly

Tap or click the matching colour as fast as you can across a run of words.
3
See the conflict cost

Your result shows your speed and accuracy, and how much the mismatched words slowed you down.

When it comes in handy

Attention check

See how well you hold a rule in mind when your instinct pulls the other way.

Focus warm-up

Use it as a quick mental warm-up before work that needs concentration.

Psychology demos

Show the Stroop effect in a classroom or to friends in under a minute.

Instant & 100% private — nothing is uploaded

Every game runs right here in your browser, and your best scores are kept on your own device. Nothing is sent to a server, so there is no sign-up and no account. Load the page once and it keeps working even if you go offline.

Frequently asked questions

What is the Stroop effect?: It is the way reading gets in the way of naming. Because reading is automatic for fluent readers, a word like "red" printed in blue creates a small conflict your brain has to override, which makes you slower and more error-prone than when the word and colour agree.
What counts as a good result?: High accuracy with a steady speed is the goal. Most people are noticeably slower on the mismatched words than the matching ones, and a smaller gap between the two suggests stronger attention control. Compare your own runs rather than chasing a fixed target.
Is this a medical or diagnostic test?: No. It is a fun, informational version of a well-known attention task. It is not a clinical assessment and should not be used to diagnose anything.
Are my best scores saved?: Your best result for each game is kept in your browser so you have something to beat next time. It lives only on this device, so clearing your browser data or switching to another device starts you fresh. Nothing is tied to an account because there is no account.
Does anything I do here get sent to a server?: No. Every game runs locally in your browser. Your scores and any text you type stay on your own device, nothing is uploaded, and nothing is logged or stored by us. Once the page has loaded it keeps working even if you go offline.