Online metronome

Set the tempo and the number of beats in a bar, and press play. The first beat of each bar is pitched higher so you can hear where the bar starts without counting.

Each click is scheduled with the Web Audio clock rather than played when a JavaScript timer happens to fire, which matters more than it sounds: browser timers are throttled by background tabs and delayed by anything else on the page, so a naive metronome audibly drifts. Scheduling ahead against the audio clock keeps it steady. On practice: the tempo where you can play something cleanly is the tempo to practise at, and most people choose one about twenty percent too fast and rehearse their mistakes into place.