How to play
- Tap the play area, click it, or press Space to start.
- Wait while the screen says WAIT.
- When it changes to TAP!, tap as fast as you can.
- Tapping too early is a false start. Tap again to restart.
About this game
Reaction Time is the simplest stage in the arcade. The screen sits in a waiting state for a random moment, somewhere between one and a half and four seconds, and then it flips to a bright signal. Your job is to tap, click, or press a key the instant you see it. The game measures the gap between the signal appearing and your input arriving, in milliseconds.
Because the delay is random, you cannot count your way to a good score. If you tap while the screen still says to wait, that is a false start. The round ends at once and you start again, so guessing never pays off.
Results move around from round to round. Attention, tiredness, and how you hold your phone all play a part, so try a few rounds before you judge a number. Many people find their times settle after a short warm-up. Your fastest time is kept as your personal best in this browser, and your last time is shown next to it.
On a phone, rest a thumb just above the screen. On a computer, keep one finger on the space bar. Either way, watch the middle of the play area rather than the edges.
What this does not measure
This game is for fun. It is not a medical, cognitive, or driving test, and it does not measure intelligence or health. Screens, touch panels, and browsers each add their own delay, so scores are not comparable between devices.
Your best score is saved in this browser only.