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Level

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Score

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Streak

100%

Accuracy

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Reaction

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Avg Reaction

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Best Score

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Stroop effect

Stroop Color Challenge

Answer what is asked, not what is shown. Matching rounds are mixed in, so your Stroop effect (how much the clash slows you) is measured too.

Test

Name the colour the word is drawn in. The classic test.

Mode

One life: a miss or a timeout ends the run.

Colours

Safe set tuned to stay apart under red-green and blue-yellow colour blindness. Not sure how you see these? Try the Color Blindness Simulator.

Back to Games

Your progress: Ink colour

Saved on this device only. 0 games played, best score 0.

Play a round to start your history.

Compare with your plain reaction time

Measure a plain reaction (no choice) in the Reaction Time Test, then type its median here. Nothing is read from that tool.

Between 80 and 2000 ms.

  • 100% Free
  • No Sign-Up
  • No Credit Card
  • No Free Trial
  • No Pro Tier
  • No Watermarks

Nothing is uploaded. Just open it and start.

Stroop Color Challenge

A color word appears in an ink color, usually not the one it names — tap the actual color, not the word. Five tests, a daily 30-round challenge, and a measured Stroop effect that is tracked over time. A fast, focused way to exercise attention and cognitive control. Free, no sign-up, no download.

A real Stroop score

Matching rounds are mixed in, so the game reports how many milliseconds a clash costs you, saved per day for each test.

Five tests, four modes

Ink colour, Reverse, Emotional, Spatial and Number, in Classic, 30 or 60 second Time Attack, or the Daily 30.

Daily challenge

The same 30 rounds for everyone each day, with a share card that carries your score and Stroop effect.

Compare with plain reaction

Type your plain reaction time from the Reaction Time Test to split the slowdown into choosing and clashing.

Progress history

Best score, accuracy and Stroop effect per day, plus personal bests for each test, kept on your device.

Colour-blind safe and private

A palette checked under red-green and blue-yellow colour blindness. Runs in your browser; nothing is uploaded.

How to Play

  1. 1. Pick a test and a mode. Ink colour is the classic.
  2. 2. Read the question above the card: what colour is the ink, what does the word say, where is it, how many.
  3. 3. Answer the question, not the distraction. Buttons are labelled and numbered.
  4. 4. Matching rounds appear now and then on purpose; they are your baseline.
  5. 5. Check Your progress for your Stroop effect and compare it with your plain reaction time.

About the Game

The Stroop Color Challenge is a small, self-contained brain-training exercise built around the classic Stroop effect: naming the ink color of a word is slower and more error-prone when the word itself names a different color, because reading is automatic and competes with color naming. Answering quickly and correctly exercises attention, focus, and cognitive control — the ability to suppress an automatic response in favor of the one the task actually asks for.

It's meant to be a fun, quick mental exercise, not a medical or diagnostic tool. Playing it doesn't diagnose an attention condition and doesn't guarantee improved focus in daily life — it's simply a game that happens to lean on the same response-control skills you use every day.

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Frequently asked questions

How do you play the Stroop Color Challenge?
A word appears in an ink colour. In the main test you tap, click or press the number key for the colour the letters are drawn in, ignoring what the word says. Most words name a different colour; about one round in four is a matching round on purpose. A correct answer starts the next round after a brief pause. In Classic a wrong answer or running out of time ends the run; in the 30 and 60 second modes and the daily challenge it only resets your streak.
What is the Stroop effect, and how do you measure it?
Reading a word is automatic, so naming an ink colour is slower when the word names a different colour. The game mixes in matching rounds and reports the difference between your average time on correct clashing rounds and correct matching rounds, in milliseconds. It needs at least 3 correct answers of each kind, so very short runs show a dash. It is saved per day for each test, so you can watch it change over weeks. Averages from a few dozen rounds are noisy; treat a single number as a rough guide.
What are the five tests?
Ink colour is the classic. Reverse asks what the word says and ignores the ink. Emotional shows everyday words (TABLE, CLOUD) and upsetting ones (GRIEF, FEAR) and asks for the ink colour, so the effect is the slowdown on upsetting words. Spatial asks where the word sits on the card (LEFT may appear on the right) and uses the keys 1 to 4 or the arrow keys. Number shows a digit repeated and asks how many digits there are, so 222 is three. Each test keeps its own best score.
What is the daily challenge?
Daily 30 deals the same 30 ink-colour rounds to everyone on a given date, using your own local date. Difficulty depends on the round number rather than on how well you play, so scores are comparable, and a miss does not end the run. Only your first finished daily of a day is recorded; playing it again is practice. The share card carries your score, accuracy and Stroop effect.
What is the difference between Classic and Time Attack?
Classic is one continuous run that ends the moment you answer incorrectly or the per-round timer runs out. Time Attack gives you a fixed 30 or 60 seconds and lets you keep going through a miss, so the goal is the highest score before the clock hits zero.
Does the game get harder as I go?
Yes. As you clear rounds, more answers unlock (up to six colours or digits), the time you have to answer each round shrinks, the pause between rounds gets tighter, and from level 4 the clashing colour is more often one that is easily confused with the real one.
How do I compare the result with my plain reaction time?
Measure a plain reaction (no choice) in the Reaction Time Test, then type its median into the box under Your progress. The tool is not linked to that one and reads nothing from it. You then see how much slower your matching rounds are than a plain reaction (the cost of choosing an answer) and how much more a clashing round adds (the Stroop effect).
Is my score saved?
Best score, best streak, fastest and average reaction, games played, a per-day history (best score, accuracy and Stroop effect for each test), your daily results, your settings and the plain reaction time you type are stored in your own browser. Nothing is uploaded, there is no account, and no server sees your results.
Is this a medical or diagnostic test?
No. It is a quick, fun mental exercise built around a well-known psychology task, not a clinical assessment. It does not diagnose attention conditions or emotional difficulties and does not guarantee any lasting improvement.
Is it accessible if I'm colourblind?
Every answer button is labelled with text, and correct and wrong answers show a tick or a cross as well as colour. Choose Colour-blind safe under Colours for an ink set checked to stay apart under red-green and blue-yellow colour blindness. If you are unsure how you see colours, try the Color Blindness Simulator. The word is always drawn on a dark card, so the inks look the same in light and dark mode. The spatial and number tests do not use colour at all.
Is it really free, and does it work offline?
It is completely free with no sign-up and nothing to install. The whole game runs client-side, so once the page has loaded it keeps working even with a flaky connection.

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