WAV, AIFF, FLAC or MP3 · analysed locally in a few seconds
analysing…
onset detection followed by autocorrelation: the analyser marks where the hits land, then finds the interval that best explains them. autocorrelation can't always tell half-time from double-time, so when it matters the reading shows the alternative too: if 78 BPM feels slow, try 156.
a chromagram, a measure of how much energy the track puts on each of the twelve pitch classes, matched against key profiles. you get the two best readings, weighted, because relative major/minor pairs share the same seven notes and real mixes are noisy. when the two scores are close, trust your ear.
no. the file is decoded in-memory and analysed in a Worker on your machine, usually in a few seconds. there is no server.
WAV, AIFF, FLAC, MP3 and M4A. anything your browser can decode works.
set the metronome or drum sequencer to the tempo, hold the tonic under your practice with the drone, or take the track to the slow-downer and learn it at half speed.