Key Finder from Chords

This key finder reads chords and tells you the key: type the chords or paste a song to find out which key it is in.

Try:

The key appears here as soon as you type a chord.

How to find the key of a song

  1. Type or paste the chords. A few chords in order are enough (G D Em C). You can also paste a whole song with chords above the lyrics or in [brackets]: the lyrics are ignored.
  2. Read the answer. The most likely key appears at once with how sure the tool is (sure, likely, not sure) and the other possible keys.
  3. Check the reasons. The tool says why: how many chords belong to the key, whether the song starts and ends on the home chord, and how many V → I movements it found.
  4. Move it to your key. Press "Transpose these chords" to open them in the chord transposer, or find a capo for easy shapes.

Worked examples

What the key finder says about four short progressions
ChordsKey foundHow sureAlso possible
G D Em C GG majorsureE minor, D major
Am F C GA minorlikelyC major, G major
Am F C G E7 AmA minorsureC major, G major
C F G7 CC majorsureF major, A minor

Am F C G: A minor or C major?

These four chords belong to both C major and A minor (relative keys share the same chords). In A minor they are i – VI – III – VII; in C major they are vi – IV – I – V. With no other clue the tool says "likely" and offers both. Add an E7 before the last Am and the answer becomes A minor with more certainty: E7 → Am is the V → i movement of A minor.

C F G7 C

Starts and ends on C, and G7 → C is a V → I cadence: a clear C major (I – IV – V7 – I).

How to find the key by hand

  1. List the chords without repeats, and note which comes first and last.
  2. Find keys that contain them. Every major key has three major chords (I, IV, V), three minor chords (ii, iii, vi) and one diminished chord (vii°). The transposition chart lists them for all 12 keys.
  3. Look for the V → I. A major or 7th chord followed by the chord a 5th below (D7 → G, E → Am) usually lands on the home chord.
  4. Choose between relative keys. If both C major and A minor fit, the home chord decides: C or Am at the end, after G or E.
  5. Allow for borrowed chords. One chord outside the key (B♭ in C major, E major in A minor) doesn't change the answer.

Tips

Capo songs

If the chords are written as capo shapes (for example "capo 2" at the top), the key the tool finds is the key of the shapes. Add the capo fret to get the sounding key: G shapes with capo 2 sound in A. The capo calculator does this for you.

Songs with very few chords

Two chords can fit several keys. Add the chords of another section, or the chord the song ends on, and the answer becomes clearer.

Frequently asked questions

How do you find the key of a chord progression?

Look for the key whose seven chords contain most of your chords, then check which chord feels like home: songs usually start or end on it, and the V chord (often a 7th, like D7 in G) leads straight into it. The key finder above weighs all of these clues at once.

What key is Cmaj7 in?

A single chord belongs to more than one key. Cmaj7 is the I chord of C major and the IV chord of G major (and the III chord of A minor, the VI chord of E minor). The other chords of the song decide which one it is: Cmaj7 with Dm7 and G7 points to C major; Cmaj7 with D and Em points to G major.

How can I tell if a song is in a major or a minor key?

A major key and its relative minor share the same chords (C major and A minor), so look at the home chord: a song that settles on Am, especially after an E or E7 chord, is in A minor; one that settles on C after G or G7 is in C major.

Is the first chord always the key?

Often, but not always. Many songs start on the home chord, but some start on IV, vi or V. The last chord is a strong clue too, and so is any V → I movement. That is why the tool shows its confidence and the other likely keys.

Do slash chords and 7th chords change the result?

The key comes from the chord itself: D/F♯ is a D chord, and Am7 counts as an A minor chord. A dominant 7th (like E7) is a strong clue, because it usually leads to the chord a 5th below (E7 → A or Am).

What if a chord is outside the key?

Songs often borrow a chord from another key, like B♭ in a C major song or D7 leading to G. The tool marks these as "borrowed or passing" and still finds the key from the other chords.

Can a song change key?

Yes. Some songs move to a new key for the last chorus, for example up one or two semitones. Paste each part separately to find the key of each section.

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