Metronome — Online & Free

A click that drifts is worse than no click at all. Browser timers are not built for musical accuracy, because they stall whenever the page gets busy, so this Metronome never trusts one to make a sound. Every click is handed to the audio clock 100 ms before it is due, which keeps the pulse steady while the rest of the page carries on.

Tempo runs from 20 to 300 BPM, by slider, by the plus and minus buttons, by typing, or by tapping the beat you already have in your head. Bars can hold anything from 1 to 16 beats, so 5/4 and 7/4 are as easy as 4/4.

The Controls, and What Each One Changes

• Tempo: opens at 120 BPM in 4/4, the setting it loads with. The marking beside it updates as you move, so 120 reads Allegretto and 121 reads Allegro.
• Tap tempo: averages your last eight taps. Pause more than two seconds and it starts the average again rather than blending two different tempos.
• Subdivision: quarters, eighths, triplets or sixteenths. The extra clicks are quieter than the beats they sit between, so the pulse stays legible.
• Accent the first beat: puts the downbeat an octave up at 1,600 Hz against the 800 Hz of a plain beat.

The lamps across the top show which beat of the bar is sounding, driven off the same audio clock as the clicks rather than off a separate timer, so what you see and what you hear do not slide apart.

Precision: What the Readouts Actually Mean

At 120 BPM a beat is 0.5000 s and a 4/4 bar is 2.000 s, both shown to the millisecond below the controls. Tempo is held as a whole number, because a metronome marked 121.5 is not a thing any score asks for; tap tempo rounds to the nearest integer for the same reason. The one that catches people out is clicks per minute: at 120 BPM with triplets selected you hear 360 clicks a minute, but the tempo is still 120, and it is the tempo your sheet music means. There is no error message anywhere in this tool, by design: out-of-range input is clamped rather than rejected, so typing 400 in the tempo box leaves 300 and typing 5 leaves 20. Changing the tempo mid-bar takes effect on the next click rather than restarting the bar, which is what lets you push and pull the speed while playing. Press Space to start and stop without reaching for the mouse.