Key & BPM Finder — Find the Key and Tempo of Any Song
Upload any track and we'll detect its musical key (major or minor) and BPM right in your browser. Free, private, and nothing is uploaded.
Why our key & BPM finder
Key and tempo at once
Get the musical key and BPM from the same upload — no second pass, no extra steps.
Works on any audio
MP3, WAV, M4A, FLAC — drop in a song, a loop, or a beat and get a reading instantly.
100% private
Analysis runs in your browser. Your audio is never uploaded to a server.
How does this key & BPM finder work?
This tool analyzes your audio entirely in your browser using the Web Audio API — a Fast Fourier Transform for the spectrum, a chroma profile matched against major and minor key templates to find the key, and autocorrelation of the low-frequency onset envelope to find the BPM. Your file is decoded locally and never uploaded to a server, so it's fast and completely private.
Once you know a song's key and tempo you can beatmatch and harmonically mix tracks as a DJ, find compatible samples and loops as a producer, or transcribe and arrange as a musician. We also show the Camelot code (for harmonic mixing), the relative key, and estimated Energy, Danceability, and Happiness — the last three are heuristic estimates inspired by Spotify's audio features, not outputs of a trained model, so treat them as a rough guide.
Accuracy: BPM is usually within a few percent, and key detection is reliable for tracks with a clear tonal center (most pop, electronic, and rock). It can be off by a semitone or misread major/minor on ambiguous material — key changes, polyphonic jazz, or live recordings with detuned instruments. If the BPM looks doubled or halved, tap the “Tap to correct” button next to it to lock it in by hand.
How accurate is it?
This is a fast in-browser estimate, not a Spotify-grade model. Here's where it shines and where to be careful.
Best for
- ✓Electronic, pop, and rock with a steady beat
- ✓Clear tonal center (most modern productions)
- ✓DJ prep and harmonic mixing
Be careful with
- !Classical or jazz with key changes
- !Live recordings with detuned instruments
- !Polyphonic or atonal material
Key & BPM Finder FAQ
We decode your audio in the browser and analyze it with the Web Audio API — onset detection for the BPM and a chroma profile for the musical key. Everything happens locally on your device.
Any format your browser can decode: MP3, WAV, M4A, AAC, FLAC, OGG, and more. Just drag the file in or pick it from your device.
No. Your file is read and analyzed entirely in your browser. Nothing is sent anywhere — the tool works offline once the page has loaded.
BPM is usually exact for steady tracks. Key detection is a best guess from the pitch profile — reliable for most pop, electronic, and rock songs, but ambiguous tracks (key changes, mixed modes) may come back as a relative key.
Yes — completely free, no sign-up, no limits. Use it on as many tracks as you like.
Absolutely. The key and BPM are exactly what harmonic mixing and sample matching need. Find compatible tracks and drop them into your set.
The Camelot wheel is a system DJs use to mix tracks in compatible keys. Each key gets a code like 8A or 5B — tracks with the same or adjacent codes mix smoothly. We show the Camelot code next to the detected key so you can plan harmonic transitions.
They're used interchangeably. BPM (beats per minute) is the number that describes the tempo — how fast the beat goes. A 120 BPM track has 120 beats every minute, or two beats per second.
Key detection is a best guess from the pitch profile. It can slip on songs with key changes, ambiguous major/minor modes, heavy modulation, or detuned instruments. If it looks off, trust your ear — or compare with the relative key we also show.
It's great for prep — finding compatible tracks and planning mixes. For live performance, treat it as a strong hint and double-check anything critical by ear. Many DJs cross-reference with a second tool for the final call.
How does it compare?
RaoMusic vs Tunebat, Spotify, and DJ software
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Make a track in this key and tempo
Know the key and BPM? Generate an original song that fits — vocals, lyrics, and instruments — with RaoMusic's AI music generator.