This is a browser version of the psychomotor vigilance task (PVT), the standard reaction test in sleep and fatigue research.
After a random delay, the red counter starts. Stop it as fast as you can by clicking, tapping or pressing Space. Ten trials take
about a minute.
Lab average: 24 ranked FPS players on the same type of test (Rogers et al. 2024). Lab equipment has almost no delay, while
a home monitor, mouse and browser usually add some, so expect your numbers to be a little slower.