Drop in a track and get its BPM and musical key in seconds. Free, no signup, analysed in your browser.
Drop a track here to find its BPM and key
MP3, WAV, FLAC, M4A, OGG or AIFF · up to 60 MB · no account needed
Your file is analysed on your own device — it is never uploaded to a server.
Use the finder above to detect the tempo and musical key of any song. Drop in an MP3, WAV, FLAC, M4A, OGG or AIFF file and you get the BPM, the musical key with its Camelot code for harmonic DJ mixing, a confidence reading for each, and the file's length, sample rate and channel count. Your audio is decoded and analysed on your own device — it is never uploaded to a server, so nothing is stored and nothing is queued.
Three steps, nothing to install.
Drop the file into the finder at the top of this page. The tempo is detected from the track's rhythmic onsets and shown as a whole number of beats per minute, along with the half-time and double-time alternatives in case your track sits at the other reading.
The analyser measures how the energy in the audio rises and falls over time, then looks for the spacing that repeats most strongly. That spacing is the beat period, which converts directly to beats per minute.
The analyser measures how much energy falls on each of the twelve pitch classes across the track, then compares that fingerprint against the profiles of all 24 major and minor keys. The closest match is the key.
Tempo detection is most reliable on music with a steady beat — four-to-the-floor house, techno and drum and bass read very consistently. Key detection is strongest on harmonically clear material. Both results carry a confidence reading, and where confidence is low you should trust your ears. Purely percussive tracks often have no detectable key at all, and the finder says so rather than guessing.
Relative major and minor keys contain exactly the same notes — A minor and C major, for example — so they are genuinely hard to separate automatically. The finder shows the runner-up so you can decide which one your track actually sits in.
Camelot is the numbering system DJ software uses to make harmonic mixing simple. Keys next to each other on the wheel mix well, so 8A blends comfortably with 7A, 9A and 8B.
MP3, WAV, FLAC, M4A, AAC, OGG, Opus and AIFF, up to 60 MB and 20 minutes. MP3 and WAV are the most universally supported; a few M4A/AAC files cannot be decoded by every browser.
No. The file is read and analysed by your own browser. It never leaves your device, so nothing is stored, transmitted or shared.
Yes — the BPM and key finder is completely free with no account required.