Key FinderKey Finder — what key is this song in?
Upload a song to find its key and the chords it plays, bar by bar. If it changes key, you will see each section; select any part to analyze it.
Same notes as the main key: songs are often mistaken for their relative. Listen to both.
The chords bar by bar (4/4). A chord marked > comes in before the bar line (pushed). Tap a bar to play from there.
Drag on the waveform to select a part (or use the handles, the boxes or "Analyze" on a row), then press Analyze.
Frequently asked questions
How does it find the key?
It measures how much each of the 12 notes sounds through the song and compares that profile with the typical profile of every major and minor key (the Krumhansl–Kessler method). No AI: plain signal processing, in your browser.
Why does it say the relative key (A minor instead of C major)?
Relative keys share all their notes, so they are the most common confusion. The app always shows the relative key: turn on the reference chord or play both chords and trust your ear.
What is the Camelot code?
DJs number the keys on a wheel (8A = A minor, 8B = C major). Songs with the same number or a neighbor number mix smoothly.
My song is tuned to 432 Hz or half a step down. Does it still work?
Yes. It first measures how far the song sits from A = 440 Hz (432 Hz, for example) and corrects for it. A guitar tuned half a step down really sounds half a step lower, so you get the key that sounds: E♭ for chords shaped in E.
Is my song uploaded anywhere?
No. The audio is decoded and analyzed inside your browser; nothing is sent to a server.