Reaction Time Test

Reaction time is the gap between a stimulus appearing and your response to it, measured in milliseconds. For a visual cue like this test's color change, the signal travels a long way: your retina registers the change, the visual cortex processes it, your brain decides to act, and a motor command fires down your arm to your finger. That chain takes most people 200–300 ms, and the global average on click-on-green tests is roughly 273 ms. Sound reaches the decision stage sooner than sight, which is why sprinters react faster to a starting gun than to a light — and your own number drifts by tens of milliseconds with sleep, fatigue, and caffeine.

Click the pad and it turns red — your cue to get ready. After a random wait it flips to green, and a high-precision timer measures the milliseconds until your click. The delay is randomised every round, so anticipating the green never pays: click before it and the round simply resets. After five attempts you get your average, with your last and best alongside. Trust the average — single tries swing by 30–50 ms, and the first round is usually your slowest.

Part of your score is hardware, not neurons. Once your brain fires, the click still has to pass through your mouse and the green still has to be drawn on screen, together adding 10–50 ms — more on a slow TV or a low-refresh laptop panel. At the other extreme, anything under about 100 ms is not a genuine reaction but anticipation, the same threshold that counts as a false start in Olympic sprinting. To see how much of your time is hardware, measure end-to-end latency with the Input Lag Tester, your screen's speed with the Refresh Rate Tester, and your mouse with the Mouse Polling Rate Tester.

How your reaction time ranks?