Chord Identifier

Identify any chord from its notes. Type a list of note names — C E G, F# A C#, B♭ D F A — and the tool returns the chord symbol (e.g. Cmaj7, Dm7♭5, G/A), the interval list in semitones, and any alternative readings the same set of notes could imply. The algorithm knows 23 chord shapes — every common triad, all five seventh-chord qualities, add9 / 6 / m6, every ninth, the three main elevenths and the three main thirteenths — and detects inversions (slash chords) automatically. Sharps or flats spelling is your call. Pure client-side, offline.

Spelling
Chord symbol Cmaj7 Major 7th
Root C
Bass C
Intervals 0, 4, 7, 11
Notes C, E, G, B
Confidence 100%

Common chords

Click any row to load those notes into the identifier. The notes are spelled with sharps; flip the spelling toggle above if your chord book uses flats.

Name Symbol Notes (C root) Intervals

How to read the output

Chord symbol
The conventional short-form name. A letter (the root) followed by a quality suffix. Examples: C (C major), Cm (C minor), C7 (C dominant 7th), Cmaj7 (C major 7th), Cm7♭5 (C half-diminished 7th), Cdim7 (C fully-diminished 7th).
Slash chord (C/E)
Appears when the lowest note you typed is NOT the chord's root. The letter before the slash is the root; the letter after is the bass note (inversion). Common in figured-bass notation and modern chord charts: G/B means a G major chord with B in the bass.
Intervals
Semitones from the root, ascending and reduced to the nearest octave. A C major triad is 0, 4, 7; a Cmaj7 is 0, 4, 7, 11; a C9 is 0, 4, 7, 10, 14 (the 14 is the 9th, an octave plus 2 semitones above the root).
Confidence
100% when exactly one template matches the input. Lower values mean the same set of notes could plausibly be read as another chord quality — the alternative readings are listed below the result card.
Alternative readings
Some pitch-class sets are genuinely ambiguous. The classic example is C E G A: it is C6 (C major with an added 6th) AND Am7 in first inversion (Am7/C). The identifier picks the no-slash interpretation (C6) by default; expand the alternatives section to see all of them.