Tap Lightning: wait for green, then tap faster than lightning

Tap Lightning measures how quickly you react to a visual signal. Each game has five rounds. In every round the pad starts red and tells you to wait. After a random delay of between one and a half and four seconds it turns green. The moment you see green, tap the pad or press a key as fast as you can.

The game records your reaction time in milliseconds for every round and shows your average at the end. If you tap while the pad is still red you are too soon, and that round is simply replayed with a new delay. It is a game for fun, not a medical or scientific test.

Your score is your average reaction time over the five rounds, and lower is better. The result screen also shows your fastest single round and a short rating, from Keep practicing up to Lightning fast.

• One star for an average under 320 ms, two stars under 250 ms and three stars under 200 ms.
• An average under 250 ms unlocks the sub-250 achievement.
• Your lowest average is saved on this device as your best, and stars and XP are added to your profile.

In Daily challenge mode the random waiting times are generated from the date, so everyone faces the same sequence of delays today. Finishing it on consecutive days builds your streak. Free play uses fresh random delays every game.

When a run ends you can copy a friend challenge link with your seed and average, and a friend who opens it plays the same delays and sees whether they beat you. Your progress is saved locally in your browser, with no account needed.

• Mouse or touch: press the big pad. It reacts on press rather than release for the fastest timing.
• Keyboard: Space or Enter does the same as tapping the pad.
• Pause cancels the current round. When you resume, the round starts again with a fresh delay.
• Press R or the Restart button to clear your results and begin a new five-round game.

• Rest your finger lightly on the pad or key so there is almost no movement to make.
• Keep your eyes soft and focused on the middle of the pad instead of staring at one edge.
• Do not try to guess the timing. Early taps only waste the round, so respond to what you actually see.
• A screen with a high refresh rate can help, since display and device delay add to every result.
• Play a few warm-up games before judging your real speed, and rest if you feel tired.