Song Key Finder
Why Use a Song Key Finder?
DJing and harmonic mixing
Tracks in the same or related keys blend smoothly; clashing keys jar the room. The Camelot code and the compatible-keys list tell you at a glance which tracks in your crate will mix cleanly with the one you are playing.
Songwriting and sampling
Found a sample you want to flip, or a voice memo with a chord loop you love? Knowing the key lets you pick melodies, bass lines and solos that fit immediately instead of hunting by trial and error.
Learning music by ear
When you know a song is in E minor, the notes you hear stop being random — they come from a scale you can learn, transpose and improvise with. A key finder turns "what is happening here?" into a concrete starting point.
How to Find the Key of a Song
- Drop your audio file. Drag an MP3, WAV, OGG, M4A or FLAC onto the box above, or click to browse.
- Let it analyze. The song is decoded and its harmony is analyzed on your device — the first run loads a small analysis engine, then results take seconds.
- Read the result. You get the key and scale (for example C major or A minor), the Camelot code, the relative key and three compatible keys. The strength meter shows how clear-cut the answer is.
Features
Key and scale detection
All 24 keys — twelve major and twelve minor — recognized from the harmony of the middle section of the song, where the key is most stable.
Camelot wheel notation
Every result includes its Camelot code and the adjacent codes on the wheel, the standard shorthand DJs use for harmonic mixing.
Honest confidence
The match-strength meter tells you when a song sits clearly in a key and when the harmony is ambiguous or modulating.
Professional audio analysis
Powered by Essentia, the open-source audio analysis library from the Music Technology Group, compiled to WebAssembly and running in your browser.
All common formats
MP3, WAV, OGG, M4A and FLAC — whatever your browser can decode, the finder can analyze.
Private by design
Decoding and analysis happen entirely on your device. No upload, no account, no trace of your music on any server.
What Musicians Say About the Key Finder
"I prep DJ sets weekly and this replaced a desktop app for me. Drop a track, get the key plus the Camelot code in seconds, and the compatible-keys list is exactly what I need for planning transitions."
"I write songs on guitar and always get stuck asking 'what key is this in?' when I record ideas. Drag the voice memo in, get the answer, and the strength meter tells me when the idea was too vague to be sure."
"Fast, honest about confidence, and nothing gets uploaded — I use it with students to show how a song settles into its home key. Would love chord detection next."
Frequently Asked Questions
How does the key finder work?
The tool computes a chromagram (pitch-class energy) from the middle section of your song and matches it against established major and minor key profiles, using the Essentia audio analysis library compiled to WebAssembly and running in your browser.
Which audio formats are supported?
Any format your browser can decode: MP3, WAV, OGG, M4A/AAC and FLAC in most modern browsers.
Is my audio uploaded to a server?
No. The file is decoded and analyzed entirely on your device. Nothing is sent anywhere.
How accurate is the key detection?
For typical pop, rock and classical recordings the result is correct roughly 85–90% of the time. Songs that modulate or sit between keys are harder — check the match-strength meter: a low percentage means the harmony is ambiguous.
What is the Camelot code for?
The Camelot wheel is a DJ notation that makes harmonic mixing easy: tracks with the same or adjacent Camelot numbers blend well together. The compatible keys listed with your result follow the same wheel.
Does it work on phones and tablets?
Yes. It runs in any modern mobile browser — pick a file from your library and the analysis happens on the device.