tool · 02100% browserweb worker
BPM Finder
Drop any track — get its tempo. Spectral-flux onset detection + autocorrelation, with octave-folding to keep the result in the musical 70-180 BPM range.
01 · onset
Spectral flux extracts a per-frame "attack curve" — far cleaner than raw RMS for percussive music.
02 · autocorrelation
Autocorrelation of the onset curve reveals the dominant period — the beat.
03 · web worker
Analysis runs in a background thread, so long files won't freeze the UI.