Listen to the lead-in clicks, then tap any key on every beat. We'll measure how early or late your presses land relative to the metronome. Make sure the metronome sound is enabled.
Press any keys. Mash or roll several at once to measure rollover and estimate polling rate.
Rollover = how many keys register at once. Polling rate is estimated from event timing and limited by browser precision — treat it as a lower bound. Some key combos are reserved by the OS or browser.
Browser limitation: browsers cannot detect polling rates above 1000 Hz.
Auto-presses your keys in a perfect roll at a set BPM so you can watch the pattern or play along.
Click a key to cycle: unused → left hand → right hand. Order follows your keyboard layout.