# BPM & Key Finder

> To find a song's BPM and key, load the audio into the finder above. It estimates the tempo from the rhythm of the drum hits and note attacks (showing half- and double-time alternatives, since songs are often felt either way), and the key from which notes and chords dominate the harmony, matched against standard major and minor key profiles. You also get the Camelot code for harmonic mixing and the relative key. Everything runs on your device — the file is never uploaded. Results are estimates: songs that change key or tempo, or have little harmony, are harder. Tap along to confirm the BPM by ear.

URL: https://kenerateai.com/bpm-key-finder
Publisher: Kenerate AI (https://kenerateai.com)
Last updated: 28 September 2026

## Key facts
- Outputs: BPM, key, Camelot, relative key
- Where it runs: Your browser — never uploaded
- Formats: MP3, WAV, M4A, OGG
- Cost: Free, no sign-up
- Demo "Main Stage" (Progressive house, ElevenLabs Music v2.5): prompt: Euphoric progressive house instrumental, big supersaw drop, rolling bass, uplifting piano chords, festival energy, 126 bpm
- Demo "Desk Lamp" (Lo-fi, Ken Music 1.5): prompt: Lo-fi hip-hop beat for studying, dusty drums, jazzy Rhodes chords, vinyl crackle, soft bass, 80 bpm
- Demo "Fog Road" (UK drill, Ken Music 1.5): prompt: UK drill beat, sliding 808 bass, skippy hi-hats, dark piano melody, eerie strings, 142 bpm
- Demo "Snowfall" (Solo piano, ElevenLabs Music v2.5): prompt: Solo piano ballad, tender and cinematic, simple memorable theme, soft dynamics swelling in the middle, concert grand

## Steps
1. Choose a file — MP3, WAV, M4A or OGG, up to 60 MB.
2. Wait a few seconds — Tempo and key are estimated on your device.
3. Check the BPM — Tap along; consider half/double time.
4. Use the Camelot code — Mix with tracks one step around the wheel.
5. Make a matching track — Open the studio with the key and BPM filled in.

## In depth

### How the finder works
Two analyses run on a mono copy of up to 90 seconds from the middle of the track:
- Tempo — it measures how the spectrum jumps at each hit (spectral flux), then finds the repeating period with autocorrelation, checking 2×, 3× and 4× the beat.
- Key — it sums energy per note name (chroma) and compares it with standard major and minor key profiles (Krumhansl–Kessler).
- Camelot and relative key — looked up from the detected key.

### Using BPM and key
Common reasons to check:
- DJ mixing — match tempos and neighbouring Camelot keys.
- Sampling and remixing — know the key before you add parts.
- Practising — set a click track to the song's BPM.
- Making a matching track — generate an original at the same key and tempo.

References:
[1] MDN — Web Audio API: https://developer.mozilla.org/en-US/docs/Web/API/Web_Audio_API

## FAQ
Q: How do I find the BPM and key of a song?
A: Load the audio file into the finder above; it estimates the tempo, key, Camelot code and relative key in your browser in a few seconds.

Q: How do I find what key a song is in?
A: Use the finder, or by ear: find the note that feels like 'home' (usually the last bass note), then check whether the song sounds major (bright) or minor (darker).

Q: Is the BPM and key finder free?
A: Yes — it's free, needs no sign-up, and runs on your device.

Q: Is my song uploaded?
A: No. The analysis runs locally in your browser with Web Audio; the file never leaves your device.

Q: Why does it show half or double the BPM I expected?
A: Many grooves can be counted either way — trap and drill are often felt at half time. The finder shows both alternatives; use tap tempo to decide.

Q: What is the Camelot code?
A: A DJ notation for keys on a wheel (1A–12B). Tracks with the same number, or one step away, usually mix harmonically.

Q: How accurate is it?
A: It's an estimate. Steady, drum-driven songs are most reliable; free-tempo, modal or key-changing music is harder for any detector.

## Related pages
- BPM changer: https://kenerateai.com/bpm-changer
- Click track generator: https://kenerateai.com/click-track-generator
- Slowed + reverb maker: https://kenerateai.com/slowed-reverb-maker
- Music genre generator: https://kenerateai.com/music-genre-generator

## Sources
- MDN — OfflineAudioContext: https://developer.mozilla.org/en-US/docs/Web/API/OfflineAudioContext