Reaction Timer

Test your reflexes by clicking the instant the panel turns green.

Measure one clean reaction. No account or score upload.

Best --

Average human reaction time is roughly 200 to 250 ms.

Rules and details

Rules

Start a round and wait for the panel to turn green.
Click as soon as the green signal appears.
Clicking during the waiting phase counts as a false start.
Your score is the elapsed time between the signal and your click. Lower is better.

The first click after a completed round starts another round. The best result is kept for this tab only.

Reaction-time tests became common in psychology and human-factors research during the nineteenth and twentieth centuries. Simple visual-response tests are still used to study attention, decision speed, and hand-eye coordination. This browser version keeps the experiment short and playful.

Privacy

The signal delay, reaction time, and best score are calculated locally. No account or network request is required.