Song key finder

Enter the chords of a song and this tool tells you which key they belong to, and how well each chord fits.

keys compared: 24, major and minor
chords to start: 2
diatonic chords: 7 per key
runs in: your browser

the key findertap two or more chords and the matching keys rank below

Tap the chords in the song

Pick at least two chords. The order does not matter.

What is a song key finder?

A song key finder compares selected chords with twelve major keys and twelve minor keys. This tool ranks candidates by matching chords and shows up to three tied best matches. It accepts major, minor and dominant seventh chords, comparing diatonic triads plus the V7 of each key. Your selection is an unordered set: the tool does not analyse a recording, melody, chord duration or where a chord appears in the song. Two chords are enough to start, but adding more does not always identify one key. Relative major and natural minor share the same diatonic triads, so listen for the tonal centre and how phrases resolve before choosing between them. An unmatched chord might be borrowed, a secondary dominant, or evidence of a key change. Use the results as candidates to check by ear, rather than a confirmed key.

24keys compared on every tap

7diatonic chords in a major key

2chords are enough to start

Learn & referenceExamples, charts and deeper explanation

Key signatures, and the chords inside each key

A key signature is the list of notes that get sharpened or flattened so the major scale comes out right. Those same accidentals decide which seven chords the key owns, and the order of qualities never changes: major, minor, minor, major, major, minor, diminished.

Key	Key signature	The seven diatonic chords
C major	none	C, Dm, Em, F, G, Am, Bdim
G major	1 sharp (F#)	G, Am, Bm, C, D, Em, F#dim
D major	2 sharps (F#, C#)	D, Em, F#m, G, A, Bm, C#dim
A major	3 sharps (F#, C#, G#)	A, Bm, C#m, D, E, F#m, G#dim
E major	4 sharps (F#, C#, G#, D#)	E, F#m, G#m, A, B, C#m, D#dim
F major	1 flat (Bb)	F, Gm, Am, Bb, C, Dm, Edim
Bb major	2 flats (Bb, Eb)	Bb, Cm, Dm, Eb, F, Gm, Adim

Sharps arrive in the order F, C, G, D, A, E, B and flats in the reverse order, which is why a key signature is always a prefix of that sequence. Every chord above opens from the chord dictionary.

Four chords that share a key signature

Tap C, Dm, Em and Am into the picker. All four fit both C major and A natural minor, which share a key signature. Listen for whether C or A feels like the tonal centre. The labels below show their functions in C major; each diagram links to its chord page.

C major chord diagram: A string at fret 3 with the ring finger, D string at fret 2 with the middle finger, B string at fret 1 with the index finger — C major, the I

D minor chord diagram: G string at fret 2 with the middle finger, high E string at fret 3 with the ring finger, B string at fret 1 with the index finger — D minor, the ii

E minor chord diagram: A string at fret 2 with the middle finger and D string at fret 2 with the ring finger, all other strings open — E minor, the iii

A minor chord diagram: D and G strings at fret 2 with the middle and ring fingers, B string at fret 1 with the index finger — A minor, the vi

How key finding works

A major scale produces seven diatonic triads: in C major they are C, Dm, Em, F, G, Am and Bdim. A natural minor uses the same triads, so matching this family narrows the choices without identifying the tonal centre.

Write the chords down. List every chord the song uses, in playing order where you know it. Order matters less than you expect for the first pass, but the opening and closing chords matter a lot.
Tap two or three of them above. Start with two chords and add the others you know. The picker accepts major, minor and dominant seventh chords, such as C, Am and G7. Major sevenths, minor sevenths and diminished chords are not selectable here.
Read the best match, then the ties. The tool ranks 24 keys by matching chords and displays up to three tied best matches. A tie can extend beyond those three. Compare the melody, phrase endings and sense of rest; the opening and closing chords are clues, not guarantees.
Confirm at the end of the song. Play the final chord and hum the note it lands on. If that note sounds like home, the key is confirmed; if it sounds tense, try the runner-up. The circle of fifths shows the neighbouring keys that a borrowed chord usually comes from.

Relative major and minor pairs

Every major key has a relative minor three semitones below it. They share a key signature and the same diatonic triads in the natural minor scale, but have different tonal centres. They can tie in this finder; listen for the tonic to distinguish them. Harmonic and melodic minor introduce additional notes and chords.

no accidentals

C major: A minor

sharps

G major: E minor
D major: B minor
A major: F# minor
E major: C# minor

flats

F major: D minor
Bb major: G minor

The same pairs appear as tracks on the circle of fifths, and the scale library shows which notes each one contains.

Key finder FAQ

How do you find the key of a song from its chords?

Compare the chords with those of candidate keys, then listen to the melody and phrase endings for the tonal centre. Matching two or three chords narrows the choices but does not necessarily distinguish relative major and minor. The first and last chords can help, but do not confirm the key on their own.

What if the song uses a chord that is not in any key?

A song need not stay inside one diatonic chord family. An unmatched chord might be borrowed, a secondary dominant, part of a key change, or a transcription error. Check its notes and role in the progression. The candidate with the most matches is a starting point, not proof of the key.

Major key or minor key: how do I tell?

A major key and its relative natural minor share the same diatonic triads. Listen for the note and chord that feel like home throughout the melody and phrase endings. C as the tonal centre suggests C major; A suggests A minor. One opening or closing chord is not enough to settle every case.

How many chords do I need to identify a key?

Two chords are enough to use this tool. There is no fixed number that guarantees one answer: even a full diatonic chord set can fit both a major key and its relative natural minor. Use the melody and phrase resolutions to identify the tonal centre.

Cannot name the shapes you are holding yet? The chord identifier names them from the frets, and Let It Be is a good first song to test the method on, since its sheet prints the key and every section.

By Chiye · Updated October 18, 2026