Find the tempo of any track in your browser.
Drop in an audio file or tap the mic. Detection runs entirely on-device — nothing is uploaded, nothing is stored.
Tap to listen · 15 seconds
Detected tempo
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BPM
From waveform to tempo, in four steps.
- 01 — Decode Audio decoded with the Web Audio API and mixed down to mono.
- 02 — Onset envelope RMS energy difference computed in 512-sample hops.
- 03 — Autocorrelation Strongest peak found across the 50–200 BPM lag range.
- 04 — Confidence Coefficient of variation of the onset envelope.