How to use it
- Click the box to start and wait: it turns green after a random delay.
- Click as soon as it is green. Clicking early repeats the round.
- After 5 rounds, see your average reaction time.
Questions and answers
What is a normal reaction time?
For a visual signal most people average 200 to 300 milliseconds. Under 200 ms is very fast; trained gamers and athletes often reach 150 to 180 ms.
Why do my results vary?
Attention, tiredness, the screen and the mouse all add delay. A 60 Hz screen alone can add up to 16 ms, so compare results on the same device.
Can I use the keyboard?
Yes, press the space bar instead of clicking.