Reaction Time Test
Test your reflexes with a simple click-when-it-turns-green reaction time test, and track your recent results.
Reaction time — the gap between something happening and your body responding to it — sits at around 200 to 250 milliseconds for the average adult reacting to a visual cue, a number that's been measured and re-measured in psychology labs for well over a century. It's not something you consciously control, which is exactly what makes it an interesting thing to test: unlike a strength or memory exercise, a reaction-time test measures a piece of your nervous system's wiring more or less directly.
Athletes, gamers, and anyone curious about their own reflexes use tools like this less to "train" reaction time in any dramatic sense — the underlying physiology doesn't change much with practice — and more to get a baseline number and see how it shifts with sleep, caffeine, fatigue, or time of day. It's a genuinely different kind of measurement than anything else on this site: instead of measuring elapsed time between two events you control, it measures the one variable you can't fully control, which is how fast your own brain and body respond.
The test itself is simple by design, because any added complexity would just be measuring something else: wait for the signal, then respond as fast as you can. The tool records the exact millisecond gap between the cue appearing and your response, which is the only number that actually matters here.
- Click the box to start.
- Wait for it to turn green — don't click too early.
- Click the instant it turns green.
- Your time in milliseconds appears, and your recent scores are tracked below.
Average human reaction time is around 200–250ms; under 200ms is considered fast.
The test resets and asks you to try again — clicking before green doesn't count.
It's a fun approximation using your browser's timing — good for casual comparison, not clinical measurement.