Wait for the screen to turn green, then click as fast as you can. A free, browser-based visual reaction time test with rounds, averages, and a best-score tracker.
This test measures visual reaction time — how quickly you can respond to something you see change. It's the same basic skill involved in driving, sports, and gaming, where a fraction of a second of response time can make a real difference.
Click anywhere to arm a round. The screen stays red for a random delay of 1.2–4 seconds, then flips to green — click (or press Space) as fast as you can the moment it does. Clicking before green counts as a false start and restarts the round. Your time is recorded across a set number of rounds, and the average of your best run is saved on this device.
Press Start exercise, set the number of rounds (3–10) in the controls panel, then click to arm each round and watch closely for the color change.
Keep your hand or finger resting near the click area rather than moving toward it after you see green — most of the delay in a first attempt is often movement time, not perception time. Typical adult visual reaction times fall in the 200–350ms range, a bit slower than auditory reaction time.
Timing is measured with standard browser JavaScript timers, so results are a useful relative benchmark rather than a lab-grade measurement, and this isn't a medical or diagnostic test — see the Disclaimer for details.