Online metronome
Sound generated in your browser · nothing downloaded or streamed
Set the tempo from 30 to 260 and the number of beats in a bar, then press play. The first beat of each bar sounds at 1600 Hz against 1000 Hz for the rest, so you can hear where the bar starts without counting.
How to use the metronome
Every click is a short synthesised blip rather than a recorded sample: an oscillator at 1600 Hz for the downbeat and 1000 Hz for the rest, opened over a millisecond and shut over fifty. Nothing is downloaded, so the page keeps working with the network off and a two-hour session costs no bandwidth at all.
The timing is good enough for practice and is not a studio reference, and the difference is worth stating plainly. Each blip is handed to the Web Audio engine 20 milliseconds before it should sound, so the note itself lands cleanly and its envelope is sample-accurate. But the moment that hand-off happens comes from a JavaScript interval timer, and browsers deliver those on a best-effort basis: layout, garbage collection and anything else competing for the main thread can push a callback late by tens of milliseconds, and the click goes late with it. A tab left in the background is throttled harder still. Keep the tab in front, and treat a stray click as the browser rather than your counting.
There is a second, quieter effect that only shows up over a long take. An interval is set in whole milliseconds, and most tempos do not divide evenly into 60,000. At 137 BPM a beat should last 437.956 ms and the timer gets 437, so the metronome actually runs at 137.30 BPM and lays down about 1.2 beats more than it should across four minutes. The error is always in the fast direction and grows with the tempo: negligible at 90 BPM, a third of a per cent at 260. Seventeen tempos divide exactly and have no error at all: 30, 32, 40, 48, 50, 60, 75, 80, 96, 100, 120, 125, 150, 160, 200, 240 and 250. Anything you record to should be tracked against a DAW click rather than this one.
On practice itself: the tempo where you can play something cleanly is the tempo to practise at. Most people choose one about twenty per cent too fast and rehearse their mistakes into place.
What people use it for
- Practising a passage slowly enough to play it cleanly
- Holding the tempo through a section that always runs away
- Bringing a piece up in steps of five BPM over a week
- Checking a piece against the tempo marked on the score
- Giving a group a count-in everyone can hear
- Setting a walking or rowing cadence away from an instrument
Questions
It marks the downbeat at 1600 Hz against 1000 Hz for the others, so you can feel where the bar starts without counting.
You cannot switch it off from the panel. Setting beats per bar to one makes every click the higher accent tone rather than removing the accent, so the practical choice is a large bar count, which puts the downbeat far enough apart to ignore.
A little, in two ways. Whole-millisecond timer periods make most tempos run fractionally fast, and a busy main thread can delay individual clicks. For practice neither is audible; for recording, use your DAW’s click.
The interval between beats is set in whole milliseconds. 137 BPM wants 437.956 and gets 437, so it plays at 137.30. The gap is largest at high tempos and zero at tempos that divide 60,000 exactly.
30, 32, 40, 48, 50, 60, 75, 80, 96, 100, 120, 125, 150, 160, 200, 240 and 250. Every other value in the range runs marginally fast.
Not for anything that has to line up later. Use the click track in your recording software, which is generated on the audio clock from end to end.
Usually not, and where it does the timing degrades badly, because browsers throttle timers in inactive tabs on purpose. Keep the tab visible while practising.
Changing the tempo or the bar length restarts the sequence from beat one, so the accent lands where you expect rather than wherever the old count happened to be.
Thirty to 260 BPM, and one to twelve beats per bar. That covers a largo through a fast presto, and bar lengths from a single pulse to complex time.
Browsers refuse to start audio without a deliberate action from you, so the sound engine is only created on the first press. It is the same rule that stops pages playing at you unasked.
Slow enough to play it cleanly. If you are making mistakes, the tempo is too high, and repeating them makes them permanent.
In small steps, and only once a step is clean. Five BPM at a time, several times a week, gets further than one long session at the target tempo.
Yes, on its own page. Tap the beat there and bring the BPM back here.
Only to load the page. Every click is synthesised in your browser rather than streamed, so it keeps working offline.
No. There is no timer, no log and no account. Close the tab and nothing of the session remains.