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New Released in April 2026

Find the Key From Chords Without a Key Finder

You can find the key from chords with four quick checks, no app needed. Most songs give the key away through which chords appear, which one feels like home, and one small pattern: two major chords a whole step apart.

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No account, no download. The demo has limited content. Advanced features are in ChordRunner Premium.

  • MIDI keyboard
  • Digital or acoustic piano
  • Guitar
  • Computer, phone or tablet
ChordRunner running on a phone next to an acoustic guitar, above a piano being played

The four checks

  • Home chord: the first and especially the last chord are often the key.
  • The major pair: in a major key, IV and V are the only two major chords a whole step apart. F and G point to C major.
  • The dominant 7th: a 7 chord like G7 usually resolves to the key chord a 5th below, C.
  • The odd chord out: a chord with a note from outside the key, like E or E7 in a song full of white-key chords, often points to A minor.

Three examples

  • G, C, D, Em: C and D are the major pair, so the key is G major.
  • A, D, E, F#m: D and E are the pair, so A major.
  • Am, Dm, E7, Am: starts and ends on Am, and E7 is its dominant, so A minor.
Find the Key From Chords Without a Key Finder – ChordRunner

Find the Key From Chords Without a Key Finder

ChordRunner is a browser game that teaches piano and guitar chords: a chord appears on screen, you play it on a real instrument, and your runner jumps.

Play the demo

Major or relative minor?

C major and A minor share the same chords. Decide by the home chord and by E or E7: if the music keeps landing on Am and uses E major, it is A minor. If it rests on C, it is C major.

Train your eye with chords in one key

ChordRunner can keep every chord inside the key and scale you choose, so a round in G major only sends you G, Am, Bm, C, D, Em and F#dim. After a few rounds the families of chords start to feel familiar, and spotting the key in a new chart gets much faster.

The levels in ChordRunner

  • Beginner: major, minor, augmented and diminished chords.
  • Intermediate: adds sus2 and sus4.
  • Advanced: adds 6th, 7th and 9th chords.
  • Pro: adds 11th, 13th and altered chords; an adaptive mode adds the next family when you are ready.

Common questions

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

Check the last chord, look for two major chords a whole step apart (IV and V of a major key), and look for a dominant 7th chord, which points to the key chord a 5th below.

What key has the chords G, C and D?

G major: G is I, C is IV and D is V. C and D are the major pair a whole step apart.

How can I tell a major key from its relative minor?

Both use the same chords. Listen for the chord the music rests on, and look for the major V of the minor key, like E or E7 in A minor.

Which instruments work?

A USB MIDI keyboard, detected automatically, or a piano or guitar through the microphone. Everything runs in Chrome or Edge on a computer, tablet or phone.

How is this different from apps where you tap the screen?

Tapping trains your eyes and fingers on glass. Here you press real keys or fret real strings, and the game hears the actual notes, so what you practise is exactly what you will play on your instrument.

Is everything in the demo?

The demo has limited content. Advanced features are in ChordRunner Premium.

Your instrument is the controller.

ChordRunner is a browser game that teaches piano and guitar chords: a chord appears on screen, you play it on a real instrument, and your runner jumps. MIDI keyboard or microphone, both work.

Try the demo

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