| Wait | The screen holds on red for a random interval. |
| Tap | React the instant it turns green. |
| Tap again | Start the next attempt. |
This is the simplest test on the site and one of the most revealing. Wait for the screen to turn green, then tap as fast as you possibly can. Your reaction time is measured in milliseconds, and the number you get is a genuine measure of how quickly your nervous system turns sight into movement.
Most adults land somewhere between two hundred and three hundred milliseconds. Under two hundred is genuinely fast, and anything under a hundred and fifty usually means you guessed rather than reacted. The test punishes anticipation deliberately, because reacting and predicting are completely different things.
Do not try to anticipate the change. The delay is randomised precisely so that guessing fails, and tapping early voids the attempt. Your best times come from being relaxed and responsive, not from tensing up ready to pounce.
Keep your finger close to the screen or your hand still on the mouse. A large part of a slow score is simply the physical distance your hand has to travel, which has nothing to do with your actual reaction speed.
Take several attempts and look at the pattern rather than one result. A single reading is noisy; your typical time across five or six tries is the number that actually reflects your reflexes.
Test yourself when rested. Reaction time is markedly affected by tiredness, caffeine and concentration, which is why the same person can score fifty milliseconds apart at different times of day.
Most people fall between two hundred and three hundred milliseconds. Under two hundred is fast.
Because you tapped before the green appeared. The wait is randomised so that guessing does not work.
Somewhat. Touchscreens and displays add a little latency, so compare your results on the same device rather than across different ones.
A little, with practice and alertness, though a large part of it is simply how your nervous system is wired.
No. Reaction Test runs entirely inside this page, so it starts the moment the page opens. There is nothing to download, no plugin, and no account to create.