Stroop Test: Free Online Colour and Word Stroop Effect Test
A colour word appears in a coloured ink. Name the ink colour, not the word, as quickly and accurately as you can. You play 20 rounds and get your result at the end.
The Stroop test is a classic psychology task that challenges your attention, cognitive flexibility and mental control. Can you beat the Stroop effect?
Correct: 0
Your best: –
Ready for the Stroop challenge?
Here is an example. The word says BLUE, but the ink colour is yellow:
Some rounds match and some clash. Click, tap or use the keys R, G, B and Y. The test takes about 1 minute.
Choose the ink colour, not the word.
Your Stroop score
out of 20 correct
Very good
Please enable JavaScript to play the Stroop test.
How the Stroop test works
- Read the prompt. A colour word appears on screen, such as RED, GREEN, BLUE or YELLOW, printed in a coloured ink.
- Name the ink colour. Ignore what the word says and choose the colour it is printed in. Click, tap or press R, G, B or Y.
- Handle the clashes. In most rounds the word and the ink disagree, for example the word BLUE printed in red. A few rounds match, which gives us a baseline for your speed.
- Get your result. After 20 rounds you see your score, total time, average response time and your personal Stroop effect.
Your best score is saved in your own browser, so you can return and try to beat it.
What is the Stroop effect?
The Stroop effect is named after the psychologist John Ridley Stroop, who published his famous experiments in 1935. He found that people take longer, and make more mistakes, when they name the ink colour of a word that spells a different colour.
The reason is that reading is automatic for skilled readers. Your brain reads the word before you can stop it, and that clashes with the slower, deliberate task of naming the colour. Overriding the automatic response takes attention and mental control, which is exactly what the Stroop test measures.
What does the Stroop test measure?
- Selective attention: focusing on the colour while ignoring the word.
- Response inhibition: holding back the automatic urge to read.
- Cognitive flexibility: switching quickly between what you see and what you say.
- Processing speed: how fast you can respond correctly.
Together these abilities are known as executive function. Psychologists use Stroop-type tasks in research on attention, ageing and how the brain handles conflicting information.
Stroop test scores: what is a good result?
Because you choose your own pace, most people answer nearly every round correctly, so speed also matters. This table shows how the ratings work.
| Result | Rating | What it usually means |
|---|---|---|
| 12 or fewer correct | Keep practising | The Stroop effect won this round. Slow down slightly and focus on the ink. |
| 13 to 16 correct | Good | Accuracy dipped, which is normal when the urge to read is strong. |
| 17 or more correct | Very good | Accurate and in control. |
| 18 or more, under 1.1 seconds per answer | Excellent | Accurate and quick. |
| 19 or more, under 0.8 seconds per answer | Exceptional | Near-perfect accuracy at high speed. |
There are no official norms for this online version, and clicking is slower than speaking, so treat these ratings as a guide. Compare your own results over time for the clearest picture. The test also assumes normal colour vision.
How to improve your Stroop test score
Put accuracy before speed
A wrong answer costs you more than a slightly slower one. Find the pace where your accuracy stays high, then speed up gradually.
Focus on the colour, not the letters
Soften your gaze and look at the colour of the word as a shape. Some people find it helps to say the colour quietly to themselves before answering.
Use the keyboard
Rest your fingers on R, G, B and Y so you never have to look for a button. Fewer moving parts means faster, cleaner responses.
Look after your focus
- Play somewhere quiet, free from interruptions.
- Get enough sleep, since tiredness increases Stroop interference.
- Practise in short, regular sessions and watch your Stroop effect shrink.
More brain games to try
Want to test other skills? Try our related brain games below.
Stroop test FAQs
What is the Stroop test?
The Stroop test is a classic psychology task in which you name the ink colour of a word instead of reading the word. When the word and the colour clash, such as the word BLUE printed in red, most people slow down or make mistakes.
What is the Stroop effect and why does it happen?
The Stroop effect is the delay and extra errors you experience when the word and its ink colour disagree. It happens because reading is automatic, so your brain reads the word without being asked and that conflicts with the slower, deliberate job of naming the colour.
What is a good score on the Stroop test?
Getting 18 or more answers right at a brisk pace is a strong result, and 19 or 20 correct with quick responses is excellent. There are no official norms for this online version, and clicking is slower than speaking, so use the ratings as a guide and compare your own scores over time.
How does this online Stroop test work?
You get 20 rounds. In each round a colour word appears in a coloured ink, and you choose the ink colour with a click, a tap or the keys R, G, B and Y. Some rounds match and some clash. At the end you see your score, time, average response time and your personal Stroop effect.
What does the Stroop test measure?
It measures selective attention, cognitive flexibility, response inhibition and processing speed. Together these skills are often called executive function, the mental control that helps you ignore distractions and focus on what matters.
How can I improve my Stroop test score?
Keep your fingers on the answer keys, focus on the colour rather than the letters, and put accuracy before speed. Relaxing your gaze, saying the colour to yourself, sleeping well and practising regularly all help.
Can the Stroop test diagnose ADHD or any other condition?
No. Stroop-type tasks are used by professionals as one small part of attention and executive function assessments, but this online game cannot diagnose anything. If you have concerns about attention or memory, please speak to a qualified health professional.
Does the Stroop test measure IQ?
No. The Stroop test measures attention and mental control, which are only part of overall cognitive ability. This game does not produce an IQ score.
Can I take the Stroop test if I am colour blind?
The test relies on telling colours apart, so people with colour vision deficiency may find it very hard or not meaningful. Results will not reflect your attention or mental control in that case.
Is the Stroop test free?
Yes. It is completely free, needs no sign-up and runs in your browser. Your best score is stored only on your own device.
This Stroop test is provided for education and entertainment. It is not a clinical or diagnostic tool and does not measure IQ. If you have concerns about your attention or memory, please speak to a qualified health professional.