Somewhere between your third coffee and your second Slack notification, your reflexes are either razor-sharp or running on fumes. Five trials, one number, total clarity.
Reaction time has been studied by psychologists for well over a century, and the numbers are well established: the average adult takes roughly 200–250 milliseconds to respond to a simple visual cue, with anything under 200ms considered fast and the documented human limit sitting somewhere around 120ms. It's not just a party trick — reaction time is one of the more reliable, repeatable markers researchers use to gauge alertness, fatigue, and even broad neurological health, since it tends to get measurably slower with poor sleep, age, and divided attention, and measurably faster with consistent practice. Five trials here won't replace a lab, but it'll tell you, in about fifteen seconds, roughly where you currently stand — and whether today is a good day to be making decisions.
Wait for the screen to change colour, then click or tap as fast as you can. You get five attempts — your fastest single reaction time becomes your score. Jump the gun too early and that trial doesn't count.
Scored in milliseconds, lower is better. Your best single reaction time across five trials is what counts, and what gets logged on the leaderboard.
It takes less time than waiting for a page to load at work, which is sort of the point. Good for proving to yourself you're still alert at 3pm, or proving the opposite.
Most people land between 200–300ms. Under 200ms and you're either superhuman or you jumped early — the game will let you know which.
Informally, yes. We're not a peer-reviewed source, but anecdotally the numbers tend to improve after coffee number two.
That trial does not count. Only the trials where you reacted to the change are scored.
Screens refresh at different speeds, and mice, trackpads and touchscreens each add a little delay of their own. A few milliseconds either way is usually the device, not you.
Yes. Your fastest time is kept in your browser on this device. Clearing your site data removes it.
Reaction Time Assessment
When the panel turns green, click as fast as you humanly can. Five trials. Allegedly for science.