Song Key and BPM Finder.
Analyzes music and finds Key, Scale and BPM for any song — plus a tap tempo. Free, private, in your browser.
Click to choose a song, or drag & drop it here
Your audio is analyzed locally and never uploaded to a server.
MP3WAVFLACOGGM4A
No file handy?
Private by design — analysis runs 100% on your device.
Analyzing your track
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Initializing…
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Detecting onsets, correlating rhythm and reading the harmony…
Tempo
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BPM
Key & Scale
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waiting…
Tap tempo
Tap along with the beat — the average of your taps becomes the tempo.
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How it works
Rhythm + harmony, decoded
Onset detection
The engine scans the song for transients and builds an onset strength envelope — where the beats and hits happen.
Tempo correlation
Autocorrelation with harmonic comb scoring finds the repeating pulse, giving the BPM with half/double-time alternates.
Key from chroma
A pitch-class profile (chroma) is correlated with major and minor key profiles to name the key, scale and closest alternatives.