Flash Reflex: the guide
Wait for the signal. Tap once. See how consistent you can be across five rounds.
Play five rounds
Tap the panel to begin. Wait while it shows the waiting state, then tap as soon as it turns green. Each valid response adds one reaction time in milliseconds. Tap between rounds to begin the next wait. A keyboard user can focus the button and activate it with Space.
Avoid an early tap
Tapping before green is a false start. That attempt does not count as a completed round; tap to retry it. Anticipating a fixed rhythm will not help because the waiting period varies. Keep your attention on the panel instead of repeatedly clicking.
Read your average
After five valid rounds, the game shows each time and their arithmetic average. A smaller average beats a larger one. Your fastest average is saved in this browser. One unusually slow round affects the average, so consistency matters as well as your quickest tap.
Device differences matter
Touchscreens, monitors, input devices, and browsers introduce different delays. Compare attempts on the same setup when you want a useful personal comparison. The number is a browser-game result, not a laboratory measurement, a medical test, or a professional assessment.
If you leave the page
Changing tabs during a waiting or green state pauses that attempt so you can retry it when you return. Finish a round with the page visible. There is no application account or public leaderboard; sharing a score is optional.