Pro Metronome

This online metronome keeps time entirely in your browser using the Web Audio clock, which is why the click stays rock-steady even at 300 BPM. A plain JavaScript timer drifts because it fires "about now"; here every beat is scheduled a fraction of a second ahead against the audio hardware clock, so the pulse lands exactly where it should bar after bar.

You get real musical control, not just a speed dial. Pick a time signature from 2/4 to 12/8, choose a subdivision (quarters, eighths, triplets or sixteenths so the in-between notes tick softly), and tap each beat dot to make it an accent, a normal beat or a rest. Five click voices — click, beep, wood, tick and cowbell — let the sound cut through whatever you are playing, and the swinging pendulum plus flashing downbeat give you a visual pulse when headphones are off.

Two practice aids do the heavy lifting. Tap-tempo finds the speed of a song when you tap along four or more times, and the tempo trainer nudges the BPM up automatically every few bars so you can build a difficult passage from slow to performance speed without touching a thing. The Italian tempo name (Largo through Prestissimo) updates as you move the dial.