🎵 Online Metronome
A free online metronome with sample-accurate timing: 20–300 BPM, time signatures, accented downbeats, subdivisions and tap tempo. Space bar to start.
Space bar starts and stops. Tap tempo averages your last few taps.
At 100 BPM one beat lasts 600.0 ms.
What Online Metronome Does
This online metronome keeps a steady beat from 20 to 300 BPM, with any number of beats per bar, an accented downbeat, and subdivisions into eighths, triplets or sixteenths. Tap tempo sets the speed from a song you are hearing, and the space bar starts and stops it so your hands can stay on the instrument.
Timing is handled the way professional web audio apps do it. A JavaScript timer alone can wander by tens of milliseconds whenever the browser is busy, which you hear as an uneven click. Here, a short timer looks a tenth of a second ahead and books each click at an exact time on the audio hardware clock, so the sound itself arrives on the beat even if the page stutters.
How to Use Online Metronome
- Set the tempo with the slider, the + and − buttons, or Tap tempo
- Choose beats per bar and a subdivision
- Turn the first-beat accent on or off and set the volume
- Press Start (or the space bar) and play along
Formula Used by Online Metronome
Beat length
Milliseconds per beat = 60,000 ÷ BPM
Worked example
120 BPM with eighth-note subdivisions.
- 60,000 ÷ 120 = 500 ms per beat
- 500 ÷ 2 = 250 ms per eighth
Result: A click every 250 ms, accented every 500 ms × beats per bar.
Beat Length at Common Tempos
| BPM | Quarter note | Eighth note | Sixteenth note |
|---|---|---|---|
| 60 | 1,000 ms | 500 ms | 250 ms |
| 80 | 750 ms | 375 ms | 187.5 ms |
| 100 | 600 ms | 300 ms | 150 ms |
| 120 | 500 ms | 250 ms | 125 ms |
| 140 | 428.6 ms | 214.3 ms | 107.1 ms |
| 160 | 375 ms | 187.5 ms | 93.8 ms |
| 180 | 333.3 ms | 166.7 ms | 83.3 ms |
Traditional Tempo Markings
Approximate ranges; conventions differ between sources and eras.
| Marking | Character | Approximate BPM |
|---|---|---|
| Largo | Very slow, broad | 40–60 |
| Adagio | Slow | 66–76 |
| Andante | Walking pace | 76–108 |
| Moderato | Moderate | 108–120 |
| Allegro | Fast, lively | 120–156 |
| Vivace | Very lively | 156–176 |
| Presto | Very fast | 168–200 |
How to Read Your Result
Practice slow, then speed up
Set the tempo where you can play a passage perfectly, then raise it in small steps — 4 or 5 BPM at a time — only after it is clean. Subdivisions help most at slow tempos, where the long gap between beats makes it easy to rush.
Using tap tempo
Tap along with a recording for four to eight beats. The metronome averages the gaps between recent taps and ignores taps older than about two and a half seconds, so you can simply start tapping again to re-measure.
Limitations & Accuracy Notes
- Mobile browsers only allow sound after a tap, and some pause audio when the screen locks or the tab is in the background.
- There is no polyrhythm or tempo-ramp mode.
- Bluetooth speakers and headphones add a fixed delay between the scheduled click and the moment you hear it; the beat stays even, but it is late relative to what you see on screen.
Frequently Asked Questions
Is this online metronome accurate?
How do I find the BPM of a song?
What do the subdivisions do?
What BPM is Allegro or Andante?
How do I practice with a metronome?
Can I use it on my phone?
References & Further Reading
- web.dev — A tale of two clocks (Chris Wilson) — The lookahead scheduling technique this metronome uses