Reaction Time

Wait for green, then tap. Reaction Time shows how fast you reacted in milliseconds, and it's honest about how that number is measured.

A run is five tries. You get every time, your average, your fastest try and how steady you were. Tap too early and the try doesn't count.

There are six modes: the classic red to green, start lights like a race, go or no go, a sound cue, a vibration cue, and a 2 player duel where each of you gets half the screen. First to 3 points wins.

I spent a lot of time on the timing. The color flips in a single frame, the clock starts at the screen refresh where green can first show, and your tap is timed by the touchscreen's own timestamp. Every phone adds a few milliseconds of hardware delay, which only ever makes you slower, so your own progress stays fair to compare.

It works offline and you don't need an account.