How the reaction test works
- Tap the box to start: it turns red and you have to wait.
- When it changes to green, tap as fast as you can.
- If you tap before it turns green, the try doesn't count and is repeated.
- After 5 tries you see your average. Your best score is saved on this device.
What this test measures
It measures the time between seeing a visual stimulus (the green color) and tapping. It's a simple measure of reflexes and attention, useful to compare your tries, to play with friends or to see how tiredness affects you.
For most people, visual reaction time is around 200 to 300 milliseconds. It improves with rest, focus and practice, and gets worse with lack of sleep or distractions.
The result includes the delay of your screen and of your touch device or mouse, so it's good for comparing your own tries, not as a clinical measurement.
Things to keep in mind
- The time you see includes the delay of your screen and your input device (mouse, keyboard or touch screen), which varies between devices.
- It's not a medical test and can't be used to diagnose anything.
- Your best score is saved only in this browser; if you clear the site data, it's lost.
Frequently asked questions
What is a good reaction time?
Under 200 ms is very fast; between 200 and 300 ms is normal; above 400 ms is slow. It also depends on your screen and device.
Why does it say I tapped too soon?
Because you tapped before the screen turned green. Wait for the color change and only then tap.
Can I use it on my phone?
Yes, it works with taps. On a computer you can use the mouse or the space bar.
Are my results saved?
Only your best score, in this browser. Nothing is sent to any server.
Is it free?
Yes, it's free, needs no sign-up and runs right in your browser.