1 players · 1 minWait for green.
Then be quick.

Five goes, an average in milliseconds, and a number that is almost certainly worse than you expect.

0/5attempts

Tap the panel, or use space. Five goes, then an average.

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Why it works

What the number means.

A healthy adult reacting to something they can see lands somewhere around 250 milliseconds. Under 200 is genuinely fast. Anything under 100 means you guessed, which is why jumping early is counted as a false start rather than a brilliant score.

About 80 of those milliseconds are not you at all. They are the signal getting from your retina to your visual cortex and back out to your hand, and no amount of practice makes that part quicker.

Worth knowing

Why five goes and not one.

A single attempt tells you almost nothing. Reaction times are noisy, and one lucky go can be 60 milliseconds better than your real average for no reason worth reporting.

Five is enough to be worth quoting and few enough that nobody gets bored. The spread between your fastest and slowest is often more interesting than the average, because consistency is the thing that actually varies when you are tired.

✦ How to play

Three steps, and none of them is signing up.

1
Press to start

The panel turns red and waits somewhere between one and four seconds.

2
Tap on green

Anywhere on the panel, or the space bar. Jumping early is a false start and does not count.

3
Five times over

You get your average, your best, and the spread between them.

Questions

Reaction time test, answered.

Around 250 milliseconds is normal, 200 to 220 is quick, and consistently under 200 is genuinely good. Times drift upward with age and considerably upward when you are tired, which is the most useful thing this measures about you.
Yes, and it is worth knowing before you compare with anybody. A 60Hz screen adds up to about 17 milliseconds of unavoidable delay over a 120Hz one, and a wireless mouse or a phone with heavy touch smoothing adds more. Compare your own runs, not your number against somebody else's hardware.
Because you tapped before it turned green. The wait is randomised between one and four seconds specifically so it cannot be anticipated, and counting an early tap would make the whole number meaningless.
Yes. Space or enter both work, and on a wired keyboard they are usually a few milliseconds faster than a mouse.

The game is free forever.
The rest of it is the hard part.

EvyOS holds the goals, projects and tasks the team goes back to once the game is over.

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