Loading content...
The panel turns green at a random moment. Click as fast as you can. Most people land between 200 and 300 milliseconds.
This is a game, not a medical test. Timings vary with your device and screen.
The panel turns red while it waits a random gap.
Green means click now. Any key press on space or enter also works.
Your last ten attempts stack up with best and mean times.
reaction ms = timestamp of your click − timestamp of greenThe clock uses your device performance timer, accurate to the millisecond.
Loosen up reflexes before ranked matches.
Run a quick bracket at offsites and standups.
Spot tired days when your average drifts up.
Show human latency alongside simple physics timing.
Discover more utility-driven tools designed to enhance your workflow and technical excellence.
Take a one-minute typing test. Track net WPM, gross speed, and accuracy. No sign up, runs in your browser.
A clean online pomodoro timer. Set focus, short break, and long break lengths, then work in rounds without an account.
Enter your date of birth. See your whole life as one grid of weeks, with weeks lived, weeks ahead, and days to your next birthday.