Wait for the box to turn green, then click as fast as you can. Five rounds, millisecond precision, and a saved best time to beat.
Each session runs five rounds so a lucky or unlucky click doesn't skew your result.
Click too early and the round doesn't count — you simply try that round again.
Your fastest ever single click is kept in this browser so you always know your record.
Simple to run, surprisingly hard to master.
Simple reaction time is one of the oldest measurements in psychology — how long it takes a person to respond to a single, expected stimulus with a single, expected action. It sounds trivial, but the signal has to travel from your eye to your brain and back out to your finger, and that round trip takes real, measurable time.
Most healthy adults land between roughly 200 and 300 milliseconds on a simple visual reaction test like this one.
Fatigue, distraction, alcohol and even the screen or input device you're using can all add tens of milliseconds.
A fixed delay lets you time your click by rhythm instead of by sight, which would defeat the purpose of the test.
A single click can be a lucky guess or a false start recovery. Five rounds give a fairer picture of your real speed.
Common questions about how the test works and what counts as fast.
Clicking the box while it is still red or orange counts as a false start. That round doesn't record a time — you simply try the same round again once it turns green.
Most adults click somewhere between 200 and 300 milliseconds. Under 200ms is very fast, and times naturally vary with tiredness, screen refresh rate and input device.
A random 1.2 to 4 second delay stops you from timing your click to a pattern, so the test measures genuine reaction speed rather than rhythm guessing.
No. Your best single reaction time is saved only in this browser's local storage on this device and is never uploaded anywhere.
Yes. Tap the box the same way you would click it with a mouse. Touch and click are handled identically.