Reaction Test
Click or tap when the screen turns green. 5 rounds. Your average time in milliseconds.
Reaction Test
Wait for the screen to turn green, then click as fast as you can. 5 rounds. No clicking early.
Average human: 250ms · Athletes: ~180ms · Top performers: <150ms
What your reaction time means
Human simple reaction time — the time from a stimulus to a response — averages around 250 milliseconds for visual stimuli in healthy adults. This number is not fixed: it varies with age (faster in the mid-20s, slower after 50), caffeine intake (modest improvement, ~10ms), fatigue (significant degradation, up to 30-40ms), and even time of day (fastest in late afternoon).
Elite athletes in timing-critical sports typically test between 150-200ms. Formula 1 drivers average around 200ms. The absolute human limit for simple reaction time appears to be around 100ms — anything faster is typically anticipation rather than true reaction. Our test includes "too soon" detection for exactly this reason: clicking before the green screen is registered as a false start rather than a valid measurement.
The test takes 5 rounds because single measurements are unreliable — outliers (a sneeze, a distraction) can skew individual results significantly. Your 5-round average provides a more stable estimate.
How to increase your reaction time — science-based techniques →