How it works
- Click the blue box, or press Space, to start. The box turns red.
- Wait. After a random pause of 1.5 to 4.5 seconds it turns green: click as fast as you can.
- Repeat five times. Your average and your best stay in this browser, so you can come back and improve.
What is a good reaction time?
In a lab, adults react to a visual signal in about 230 milliseconds on average. In a browser the screen, the mouse and the browser add their own delay, so most adults average between 230 and 290 ms on a test like this one. Under 200 ms is very quick. Results above 350 ms usually mean a distraction, a tired evening or a slow screen.
Why your device matters
Screens and mice add a small delay of their own. A 60 Hz screen draws a new image every 16.7 ms, and some wireless mice, TVs and touch screens add more. A fast monitor and a wired mouse can take 10 to 30 ms off your score, so compare results on the same device.
How to get faster
Reaction time improves with sleep, focus and practice. Sit comfortably, rest your finger on the mouse button and look at the middle of the box. Don’t try to guess the moment: the pause is random, and clicking early only restarts the try.
Questions and answers
How is my reaction time measured?
The page records the moment the green screen is drawn and the moment you click or press a key, using your browser’s high-precision clock. The difference, in milliseconds, is your reaction time.
Why is the waiting time random?
If the green came after a fixed pause, you could learn the rhythm and click before seeing the signal. A random pause between 1.5 and 4.5 seconds makes you react to what you see.
Can I use the keyboard or a phone?
Yes. Press Space or Enter instead of clicking, or tap the box on a phone or tablet. Touch screens can add a few milliseconds, so compare like with like.
Are my results saved?
Your best average stays in your own browser so you can try to beat it. Nothing is sent to our servers, and Reset deletes it.
More tests
Your results stay in your browser: we don’t store them on our servers.
↑ Back to top