Key Finder: Song Key Detector

What key is this song in? Find out in seconds, free.

Key Finder detects the musical key of any song, from a file on your phone or from music playing in the room. It shows the key and its relative, the DJ key code (1A–12B), how sure the result is, the alternatives, the notes the song uses and the song's tuning. Then it tells you what to play: scale, chords and capo position. For singers, guitarists, pianists, DJs and everyone who plays by ear.

TWO WAYS TO FIND THE KEY
• File: open an MP3, M4A, AAC, WAV, FLAC or OGG song. The whole track is decoded and analysed on your phone, offline, with a progress bar and cancel.
• Listen: play the music near the phone. The estimate settles in 10 to 20 seconds and keeps following the music, with a stability indicator and a warning when the sound is too quiet.

A RESULT YOU CAN TRUST
• Key, relative key and DJ key code (8A, 9B...).
• Confidence in percent and the next most likely keys.
• Chromagram: twelve bars with the notes the song really uses, compared with the profile of the detected key.
• Tuning: the song's A in hertz and its offset in cents, for tracks tuned to 432 Hz or with an altered pitch.
• Tempo in BPM, measured at the same time.
• Key over time: modulations and key changes along the track.
• Honest about doubt: atonal or purely percussive audio says "No clear key" instead of inventing one.

WHAT TO PLAY
• Scale with correct spelling (F sharp or G flat, never guessed), and the raised seventh of minor keys.
• The chords of the key with Roman numerals: tap one to hear it.
• Guitar capo positions to play the song with easy open shapes.
• Harmonic mixing: the keys that blend smoothly with the track, for DJ sets.
• Ear check: plays the tonic chord or a drone in the song's own tuning over the music, so you can confirm the key by ear.

MADE FOR MUSICIANS
• Note names in letters (C D E), German (H) or solfege (Do Re Mi).
• Choice of key profiles (Krumhansl-Kessler, Temperley, Albrecht-Shanahan or combined).
• History of every result on your device.

FREE AND PRIVATE
No ads, no in-app purchases, no subscription, no account. Works offline. Songs and microphone sound are analysed on your device and never recorded or sent; no data collected.

Dark and light theme, 71 languages.

Made by FELICE MARRA / MUSIC STUDIOS.