Opening help cancels a waiting signal. Start a fresh attempt when you return.
Controls
- React
- Space, click or tap the panel
How to play
Wait for the panel to switch to GO, then tap, click or press Space as fast as you can. Too early counts as a false start and the round repeats.
What it measuresSimple visual reaction time: from the moment GO appears to your press. Typical results are 200–300 ms. The wait before GO is random (1.5–4.5 s) so it can't be timed in advance.
Fair comparisonsYour screen, browser and input device add their own delay, so compare results on the same device. A keyboard is often a little faster than a touchscreen.
Not colour aloneThe panel says GO as it changes colour, so the signal never depends on colour vision.
1 player · Keyboard · Mouse · Touch
Next game: Sudoku →