Key + BPM Finder
Upload a song or beat and get its key, tempo, duration and compatible keys.
MP3, WAV, M4A, FLAC · up to 100 MB
What key your song is in
The analysis extracts the harmonic content of your audio — how much each of the twelve pitch classes is present across the track — and matches that profile against the key profiles established in music research.
The result is an estimate, and we always label it as one. Songs modulate, relative keys share the same notes, and a heavily limited master can blur the analysis. When confidence is low we say so rather than pretending.
BPM, and why detectors double it
For tempo we detect onsets in the audio and look for the dominant periodicity. Every detector's classic mistake is locking onto the hi-hats instead of the beat and reporting double the BPM; we correct that by comparing how strong the accent actually is at each candidate tempo.
Live-played material without a click will give an approximate figure by nature.
Compatible keys for mixing
The compatible keys come from music theory, not a made-up list: the relative, dominant and subdominant keys plus neighbouring degrees, along with the Camelot code DJs use to mix harmonically.
Frequently asked questions
Are my files uploaded anywhere?
No. Audio is processed inside your browser and never leaves your device.
How accurate is key detection?
Reliable on material with clear harmony. Very percussive tracks, heavy modulation or crushed masters can fool it — that is why we show a confidence warning.
Which formats can I upload?
MP3, WAV, M4A and FLAC up to 100 MB. M4A support depends on your browser.
What is the Camelot code?
The wheel DJs use for harmonic mixing: neighbouring codes sound good together.