Key Finder

A key finder analyses a recording and tells you which musical key it is in — C Major, A Minor, F# Minor and so on. The key is the note the music comes home to and the scale built around it. Knowing it lets you play along, sing along, pick a compatible song to mix into, or transpose the track into a range that suits your voice.

Drop your MP3, WAV, M4A or MP4 file into the box above and press Find the key. Your song opens in the KeyPitch Audio Studio, which measures which notes are played across the whole track, compares that fingerprint with all 24 major and minor keys and shows the best match in an analysis panel, usually in a couple of seconds — with the relative key, the Camelot code and the second most likely key.

The track is split into short slices and each slice is turned into a chromagram — a measure of how much of each of the twelve notes is sounding. Adding those up over the song gives a profile of which notes matter most. That profile is then correlated with reference profiles for every major and minor key, and the closest match wins.

On clearly tonal music — pop, rock, dance, folk, classical — it is right most of the time. It has a harder time with tracks that change key halfway through, heavily distorted or percussive material, very short clips and atonal music. If the answer surprises you, check the second most likely key in the analysis panel — it is usually the relative one.

The letter is the tonic — the note that feels like home. The second word is the mode: major usually sounds bright and open, minor darker and more melancholic. So "A Major" means the music is built on an A and uses the major scale. If you play an instrument, that tells you which chords and which scale to reach for.

Every major key shares its notes with one minor key, and the other way round: C Major and A Minor use exactly the same seven notes. That pair is called relative. Because they contain the same notes, a key finder can hesitate between the two — and musically they work together, so a song in C Major sits happily next to one in A Minor.

The Camelot wheel renames every key as a number from 1 to 12 plus a letter — A for minor, B for major. It is the notation DJs use for harmonic mixing: tracks whose codes are identical, one step apart on the wheel, or share the number with the other letter will blend without clashing. 8B and 9B mix well; 8B and 8A also work.

Because a key is an interpretation, not a number stamped on the file. Two common disagreements are the relative pair — C Major versus A Minor — and songs that spend the verse in one key and the chorus in another. Different tools weigh the evidence differently. If your ear says the alternative reading is the right one, trust your ear.

They are two different things. The key is which scale and home note a song is built on, and you change it in semitones — moving up two semitones takes a song from C Major to D Major. Pitch is the reference frequency everything is tuned to, measured in Hz, where the standard is A4 = 440 Hz. This page finds the key; the Pitch Changer moves the pitch in Hz.

Yes, right in the studio it opens in. Your file is already loaded: move the Semitones slider, then open the analysis panel with the ⓘ button next to Share to read the new key — from A Minor, +2 semitones gives B Minor. You can also adjust the pitch in Hz, change the speed, add reverb or bass, then export as MP3 or WAV.

A song written for one voice rarely fits another. Once you know the original key, you can move a backing track down a couple of semitones when the chorus sits too high, or up when the verses disappear into your lowest notes. Singing teachers do this for every student, and the same file can be exported in several keys for a whole choir.

MP3, WAV, M4A and MP4 files up to 50 MB and 10 minutes work, and the key finder is completely free with no account needed. Your file never leaves your computer: the analysis runs inside your browser, so nothing is uploaded to a server.