Chord Identifier - What Chord Is This?

It compares the pitch classes you chose against about thirty chord types (triads, sevenths, suspended and added-note chords, ninths, elevenths, thirteenths, altered dominants and power chords) and tries each possible root. The lowest note is treated as the bass, so if the bass is not the root, the result is written as a slash chord, for instance C/E for C E G with E at the bottom.

Some note sets are genuinely ambiguous. A diminished seventh is made of stacked minor thirds, so every one of its four notes could be the root, and an augmented triad behaves the same way with major thirds. A set like A C E G is both Am7 and C6. The tool lists every name so you can choose the one that matches the key or the bass line.

A missing fifth is allowed, because players leave it out all the time, especially in jazz voicings and on guitar. C E Bb is still recognised as a C dominant seventh rather than rejected as unknown.

Two notes are not a chord, so it names the interval between them instead, such as a major third or a perfect fifth. Add a third note to get a chord name.

Separate note names with spaces and use # for sharps and b for flats, for example C E G Bb or F# A C#.

Yes. Chords with an added ninth, extended dominant ninths, elevenths and thirteenths are included, along with altered dominants such as 7b9, 7#9 and 7#5. Select the notes you actually play; a full 13th chord has seven different notes, and real voicings rarely include all of them.

There is no sign-up. It applies music theory rules in your browser, and nothing you enter is sent anywhere.