Song Key Finder

About the Song Key Finder

The key of a song is its home: the note and the scale that the melody and the chords keep coming back to. "A minor" means the home note is A and the mood is minor. Singers need the key to know if a song fits their voice. Musicians need it to play along. DJs need it to mix two songs without a clash.

This song key finder listens to an audio file and tells you the key. Open an MP3, WAV, M4A, OGG or FLAC file. It counts how much of each of the 12 notes the song uses, compares that with the typical pattern of every major and minor key, and shows the best match. You also get the relative key, the Camelot code for harmonic mixing, and the BPM (tempo). Everything happens in your browser — the song is never uploaded.

Features

• Key with confidence — major or minor, with a confidence bar and the 3 most likely keys
• Relative key and Camelot code — for example A minor = 8A, its relative C major = 8B
• BPM too — the tempo, with half and double time, from the same method as our BPM Finder
• Chord check by ear — play the chord of each candidate key over the song, tuned like the song
• Note chart — a bar for each of the 12 notes; the notes of the key are coloured
• Only a part — drag two handles on the waveform to check one part, such as a key change
• Tuning check — tells you when a song is tuned sharp or flat of A = 440 Hz
• Private — the song is read in your browser and never sent anywhere

How the key is found

The finder works in three steps:

1. Notes. The song is cut into short slices of about a third of a second. In each slice it finds the strong pitches between 55 Hz and 2,000 Hz and puts each one on its note: C, C♯, D … B. The octave does not matter, so a low A and a high A count as the same note.
2. Profile. All the slices are added up into 12 numbers — the bars you see in the chart. A song in A minor uses A, C and E a lot, and G♯ or B♭ only a little.
3. Match. Music researchers Carol Krumhansl and Edward Kessler measured how well each note "fits" a major or a minor key. The finder compares your song's 12 numbers with that pattern in all 24 keys (12 major, 12 minor). The closest one is the key.

It also checks the tuning first. Some recordings are a little sharp or flat (for example A = 445 Hz instead of 440 Hz). The finder measures this and moves every note back, so the key is still right.

The Camelot wheel

DJs use the Camelot wheel to mix songs that sound good together. Each key gets a number from 1 to 12 and a letter: A for minor, B for major. A key and its relative key share the same number.

Easy mixes: from your song's code, go to the same code, one number up or down (8A → 7A or 9A), or the same number with the other letter (8A → 8B). These keys share almost all their notes.

Relative keys: why two keys look alike

Every major key has a relative minor with exactly the same notes. C major and A minor both use only the white keys of a piano. The difference is the home note: in C major the music rests on C, in A minor it rests on A.

So when a song uses those notes equally, the finder may show C major first and A minor second. That is not an error — it is a real musical question. Press Chord for both while the song plays. The chord that sounds like the end of the song, like "home", is the key.

Tips for a good result

• Use the whole song for most songs. More music gives a surer answer.
• For a song with a key change (often near the end of pop songs), choose Only a part and check the parts one by one.
• Skip a long spoken intro or drum intro with the part handles.
• Low confidence? The song may change key, use unusual scales, or have no clear home note (some jazz, rap over drums only, or noise). Trust your ears and the chord buttons.
• For singing, combine the key with the Vocal Range Test: if the song is too high or low, move it with the Pitch Changer.

Frequently asked questions

What key is this song in?

Open the song on this page and wait a few seconds. The big name at the top is the most likely key, for example "E♭ minor". Below it you see the 3 most likely keys with a confidence for each.

How accurate is the key finder?

For songs with clear chords and one key it is right most of the time. When it is wrong, the right key is almost always in the top 3 — usually the relative key (same notes) or a key next to it on the Camelot wheel. It is an estimate, so check it by ear with the Chord buttons.

What does the Camelot code mean?

It is a short code DJs use for keys: a number from 1 to 12 and a letter, A for minor and B for major. Songs with the same code, a number next to it, or the same number with the other letter mix well together.

Why does it say "also written"?

Some keys have two names for the same notes, like F♯ major and G♭ major, or E♭ minor and D♯ minor. Both are correct. The finder shows the common one first.

Does it find the BPM too?

Yes. The tempo uses the same method as the BPM Finder and shows half and double time. For many songs at once, use the BPM Finder.

Is my song uploaded?

No. The song is opened and analysed in your browser. Nothing is sent to a server, so it works for unreleased music too.

Which files can I use?

MP3, WAV, M4A, AAC, OGG and FLAC — any audio your browser can play. Up to the first 10 minutes are used for the key and the first 5 minutes of the chosen range for the tempo.

Related tools

• BPM Finder — the tempo of many songs at once
• Pitch Changer — move a song to another key
• Vocal Range Test — find your lowest and highest note
• Guitar Tuner — tune up before you play along
• Metronome — practise at the song's tempo
• Vocal Remover — make a backing track to sing over

How to use it

• Press the box and choose a song, or drop the file on it
• Wait a few seconds while the finder listens
• Read the key, the Camelot code and the BPM
• Press Chord next to each of the 3 keys while the song plays, and keep the one that sounds like home
• To check one part, choose Only a part and drag the two handles on the waveform
• Press Copy result to copy the key and BPM, or Another song to start again