About the Reaction Time Test
This free reaction time test measures how long it takes you to respond to a visual signal. Wait for the screen to turn green, then click, tap or press Space as quickly as you can. Five tries give you an average, a best time and a median, and your recent results are saved in this browser so you can see whether you are improving. For a head-to-head challenge, switch to Duel vs bot: you and the bot see the same signal, and the first to react wins the round.
What reaction time measures
Simple visual reaction time is the delay between a stimulus appearing and your response. It includes the time for light to reach your eyes, for the signal to travel to the brain, for the brain to decide to act, and for your finger to move. It also includes delays added by your device and browser: the input device reports the press, the browser handles the event, and the screen has to draw the new colour. Only part of the total is yours, so use a browser test to compare your own results on the same setup.
There is no single “normal” number. Results depend on age, alertness, practice and the delay added by your screen, browser and input device, so compare your scores on the same device over time. The rating labels in this tool are a convenience for fun. They are not a medical, clinical or population benchmark.
How to get a more accurate result
- Keep the setup the same. Use the same device, browser and input method each time you compare results. A keyboard, a mouse and a touchscreen do not add the same delay.
- Know your refresh rate. A 60 Hz display redraws about every 16.7 ms and a 120 Hz display about every 8.3 ms. A new colour can only appear on the next refresh, so faster screens add less delay on average.
- Check your mouse. Mice report clicks at a polling rate, commonly 125 Hz or 1000 Hz. Higher polling shortens the wait before a click is sent, although the effect is small next to your own reaction.
- Close heavy apps and tabs. Background work can delay the browser.
- Keep the tab in front. Browsers slow down background tabs. This test cancels the current try if you switch away, so you can carry on when you return.
- Do not anticipate. The wait is random, and pressing before green counts as too soon. Guessing the timing gives a fast-looking number that is not a real reaction.
How to improve your reaction time
Simple reaction time changes slowly, but consistency improves with practice. Short, focused sessions work better than long, tired ones.
- Keep your finger ready. Rest your finger or the Space key on the input before the green appears. Less movement after the signal saves time.
- Stay relaxed and focused. Tension in the arm or shoulder can make responses less steady. Look at the centre of the screen and react to the colour, not to your own expectations.
- Look after the basics. Sleep, hydration and cutting back on alcohol all affect how quickly you respond.
How the duel works
In Duel vs bot, each round starts with a red wait. Sometimes the screen flashes orange for a moment. That is a decoy, not the real green, and clicking on it counts as jumping the gun. The bot draws its reaction time from a random distribution set for each difficulty, so it is not identical from game to game. Easy and Normal are slower and forgiving. Hard and Insane are faster. Insane is fast enough that a quick human can win, but expect to lose many rounds first. If both players jump the gun, or nobody taps in time, the round is replayed and does not count.
FAQ
Is the reaction time test free?
Yes. It runs in your browser with no download and no sign-up. Your results are saved only on this device.
What is a good reaction time?
There is no single good number. A consistent average over several tries tells you more than one lucky attempt, so compare against your own history.
Why did I get "Too soon"?
You pressed before the screen turned green. That try does not count. Tap again to retry.
Does it work on a phone?
Yes. Tap anywhere on the screen. Touchscreens and browsers add their own small delays, so compare phone results with other phone results.
Can this test diagnose anything?
No. It is a simple game, not a medical test. If you notice a sudden change in your reactions or other worrying symptoms, speak to a doctor.