Reaction Time Test

How fast are your reflexes, really

Wait for the screen to turn green, then click as fast as you can — clicking early resets the test, since the whole point is measuring reaction to the signal, not a guess at the timing. Under 200ms is genuinely fast; most people land somewhere in the 250-400ms range.

What actually affects reaction time

Visual reaction time is generally a little slower than reaction to sound, since sound processing takes a shorter path through the brain — which is part of why sprinters react to a starting gun faster than they would to a visual cue. Fatigue, screen refresh rate, input lag on the device you're using, and even simple practice at this specific test all move the number, so it's more useful for tracking your own trend over repeated tries than as an absolute measurement of "how fast are your reflexes" in general.

Why the test can't be perfectly precise

Any browser-based reaction test has some unavoidable measurement noise on top of your actual biological reaction time — screen refresh rate limits how precisely a color change can even be timed, and there's a small, variable delay between your click and the browser registering it. None of that changes the number enough to matter for casual comparison, but it's worth knowing this measures "reaction time plus a small amount of device overhead," not a laboratory-grade isolated reading of neural response time alone.

Getting a fair average, not a single lucky click

A single fast result is easy to get lucky into (or unlucky out of, with a mistimed early click), so the more meaningful number is an average across several tries rather than your single best one — take it five or six times in a row and look at where most of your results cluster, which gives a far more honest read on your actual typical reaction time than cherry-picking the fastest attempt.