BPM & Key Detector

Find the tempo and musical key of the same audio file in one analysis. Compare alternatives, confirm both values and export one report.

How to use

Load a song or the built-in example, then choose Analyze BPM & key. Audition the same audio, check half-time and double-time tempos, compare alternate keys and save both manual confirmations in one JSON report. The standalone analyzers keep the same loaded file when you switch.

Know the limits

Tempo and key are independent estimates, not certified measurements. Syncopation, relative major/minor, sparse notes, changing tempo and key changes can be ambiguous. Both analyzers use up to the first 150 seconds; listen and confirm the results.

Audio is processed on your device. JavaScript is needed to use the tool.