What is it?
Reaction Time Test measures how quickly you react. Wait for the red box to turn green, then tap or press Space as fast as you can. After five rounds you see your average, median and fastest time in milliseconds with a simple rating. The wait before green is random (1.5 to 5 seconds), so you cannot guess it.
Who is it for?
Friends challenging each other, gamers checking their reflexes, students doing a simple science experiment, and anyone curious how tiredness affects them.
How to use it
- Tap the box (or press Space) to start.
- Wait while it is red. Do not tap yet.
- The moment it turns green, tap as fast as you can. Your time for that Round appears.
- After five rounds you see, for example, Average 268 ms (median 262, fastest 231). Good: about average for adults.
- Your best is saved; Restart begins again and Clear my history deletes saved results.
What the ratings mean
- Under 200 ms: Lightning fast ⚡ (top few percent).
- 200–249 ms: Very quick: better than most people.
- 250–299 ms: Good: about average for adults.
- 300–399 ms: A little slow: try again when fresh. 400 ms and over: Slow: were you distracted?
This is a game, not a medical or driving fitness test. Never drive when tired, whatever your score.
Errors and how to fix them
- “Too soon!” with “Wait for green. Tap to try this round again.”: you tapped while it was red. The round does not count; tap to retry.
- My times are much slower on a phone: touch screens and some displays add delay. A mouse or keyboard is more accurate.
- Results vary a lot: attention, tiredness and the device all matter. That is why the median is shown: it ignores one odd result.
- My game, best time or score has gone: it is kept only in this browser on this device. Private windows, clearing site data, or another browser or phone start fresh.
Open the tool: Reaction Time Test
Still stuck?
Contact support. Tell us which tool or page you were using, what you tapped, what you saw, and your phone or computer and browser (for example: Android phone, Chrome). We reply by email.
Questions, or an error not listed here?
Tell us in the comments: what you were doing, the exact message you saw, and your device and browser. We read every comment and add new fixes to this article.