How to play
Tap to start, wait for green, then tap again immediately.
About Reflex Test
Reflex Test answers a question most of us have wondered about at some point: how fast are my reactions, really? The screen turns red, then at some unpredictable moment turns green, and you tap as quickly as you can. The game tells you how long you took, in thousandths of a second.
How it works
Tap once to begin. The screen goes red and asks you to wait. After a random pause of between one and four seconds it flips to green. Tap or click the instant you see it. Your reaction time appears in milliseconds. Tap again for another go.
If you tap while the screen is still red, the game says "Too early!" and the attempt does not count. The random wait is there to stop you guessing, and it works. You cannot get a rhythm going, so the only way to post a good time is to react to what you actually see.
What is a good time?
For a simple see-it-and-press test like this one, most adults come in somewhere between 200 and 300 milliseconds. Around 250 is typical. Under 200 is quick. A result much below 150 is more likely a lucky early press than a true reaction, because it takes the eye and brain about that long just to register that something has changed.
Do not judge yourself on one attempt. Times bounce around from try to try. Take five or ten and look at the average, or at your best three.
Why your number might be higher than you expect
Part of the time shown has nothing to do with you. Screens take a moment to change colour. Touchscreens, mice and wireless connections each add a small delay. Depending on the device, that can be anything from a few milliseconds to several dozen. A phone will often give slightly slower results than a computer with a wired mouse.
So the fairest comparison is with yourself, on the same device. And if you are comparing with a friend, take turns on one phone.
How to get faster
Get comfortable first. Hold your finger just above the screen, or rest it on the mouse button, so it only has to move a tiny distance. Tension slows you down, so keep your hand relaxed.
Look at the middle of the screen and do not try to predict the change. The more you think about when it might come, the more early presses you will make.
Your state matters more than your technique. People are measurably slower when they are tired, and quicker when they are alert and warmed up. The first couple of tries in any session are usually the worst.
Does practice help? A little. Your nerves will not speed up much, but you get better at the task itself, and most people shave a few tens of milliseconds off after a few sessions.
Things to try
Test yourself in the morning and again late at night. Compare your writing hand with the other one. Challenge the family and see whether the teenagers really are quicker than the adults. Each attempt takes a few seconds, so it is easy to run a whole tournament in a coffee break.
Reflex Test is free and runs in the browser on phones, tablets and computers, with nothing to install.