Reaction Time Test

Click the box to start, wait for it to turn green, then click as fast as you can. After 5 tries you get your average, best and median time and the standard deviation, which shows how consistent you were.

How to take the reaction time test

1. Click (or tap) the box. It turns red: wait.
2. After a random delay it turns green. Click as fast as you can.
3. Clicking while it is red counts as too soon and that round restarts.
4. After all tries you see your average, best, median and standard deviation.

What the statistics mean

• Mean (average): the sum of your times divided by the number of tries.
• Median: the middle time. It ignores one unusually slow click better than the mean does.
• Standard deviation: how spread out your times are. A small SD means you are consistent.

Example: 250, 270, 240, 300, 260 ms. Mean = 1,320 ÷ 5 = 264 ms; median = 260 ms; SD ≈ 23 ms.

Why your result varies

Screen refresh rate, mouse or touchscreen delay and browser timing add some milliseconds, so compare your results on the same device. Focus, sleep, practice and caffeine also change reaction time from day to day.

Reaction time statistics quiz: 10 questions

Test yourself with 10 multiple-choice questions. Choose an answer and press Submit to see if you are right and why. Your score appears at the end.

Frequently asked questions

What is a good reaction time?

For a simple visual click test like this, results commonly fall between about 200 and 300 milliseconds. Device delays add some time, so compare yourself on the same device.

Why do my times change so much?

Attention wanders and the random delay sometimes catches you off guard. That is why the test reports the median and standard deviation as well as the average.

Does a faster device help?

Yes, a little. High-refresh screens and wired mice add less delay.

Can I use the keyboard?

Yes. Focus the box and press Space or Enter instead of clicking.

Does practice improve reaction time?

Practice usually improves consistency and can shave off some milliseconds, mostly by learning to stay focused.

Sources

• OpenStax Introductory Statistics 2e: Measures of the Center and Spread of the Data

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