The Tools
Chord Identifier — What Chord Is This? (Notes → Name)
You are holding something and you do not know what it is called. Enter the notes — on the keyboard or on the fretboard — and we will name it: root, quality, inversion, and the intervals that make it that chord and not another one.
Build the shape you are holding
Click a fret to place a finger, click it again to mute the string. With the keyboard: arrow keys move along the string (← →) and between strings (↑ ↓), Home mutes, Enter or Space places a finger.
Matches
Pick at least two notes on the fretboard and every chord they spell appears here — best match first, with links to the full chord page.
How chord identification actually works
Identifying a chord is a three-step mechanical process, and the tool above performs exactly these steps. Doing them by hand a few times is how the skill sticks.
- Reduce to pitch classes.Octaves and doublings are thrown away. A six-string guitar chord with three E's in it contains one E as far as the name is concerned.
- Find the root. Try every note as a candidate root and stack the remaining notes in thirds above it. The note that produces a clean stack — 3rd, 5th, 7th, 9th — is the root. Usually only one candidate works; when two do, the chord has two valid names.
- Measure the intervals, then name the quality. Count the semitones from the root to each chord tone. That interval pattern is the quality: a major 3rd and a perfect 5th is major, a minor 3rd and a perfect 5th is minor, and so on down the table below. Finally, look at the lowest sounding note: if it is not the root, the chord is inverted and gets a slash name.
Intervals → quality, in one table
Every chord quality is a different pattern of intervals above the root. These eight cover the overwhelming majority of chords in popular music.
| Above the root | Formula | Quality | Example |
|---|---|---|---|
| major 3rd + perfect 5th | 1 · 3 · 5 | Major | C E G = C |
| minor 3rd + perfect 5th | 1 · ♭3 · 5 | Minor | A C E = Am |
| minor 3rd + diminished 5th | 1 · ♭3 · ♭5 | Diminished | B D F = Bdim |
| major 3rd + augmented 5th | 1 · 3 · ♯5 | Augmented | C E G♯ = Caug |
| major triad + minor 7th | 1 · 3 · 5 · ♭7 | Dominant 7th | G B D F = G7 |
| major triad + major 7th | 1 · 3 · 5 · 7 | Major 7th | C E G B = Cmaj7 |
| minor triad + minor 7th | 1 · ♭3 · 5 · ♭7 | Minor 7th | D F A C = Dm7 |
| 3rd replaced by the 4th | 1 · 4 · 5 | Suspended 4th | C F G = Csus4 |
Why the same notes get two names
Take C-E-G-A. Read from C it is C6: root, major 3rd, perfect 5th, major 6th. Read from A it is Am7: root, minor 3rd, perfect 5th, minor 7th — the identical four pitches, rooted a minor 3rd lower. Neither reading is wrong. What decides it is the music around the chord: in the key of C with a C in the bass it is C6; walking into a D minor chord from an A bass note it is Am7.
The identifier shows every valid reading and ranks the one that is in root position and exists as a real chord in our catalog first — but the alternates underneath are not runners-up, they are other true answers.
The bass note changes the name, not the chord
C major is C-E-G whichever order you stack them in. Put the E lowest and you have C/E, the first inversion; put the G lowest and you have C/G, the second inversion. Guitarists meet this constantly — G/B is the standard bridge between G and Am — so the identifier always reports which inversion you are voicing, and links the inversion's own page when we have one.
Where to go next
- Chord Finder — the same two-input engine as a general-purpose lookup tool
- All 360 chords — every chord we cover, with diagrams for six instruments
- Scale Explorer — which scales the chord you just identified belongs to
- Circle of Fifths — the key the chord most naturally lives in
- Music theory guides — intervals, chord construction and harmony in long form
FAQ
What chord is this?
How do I identify a chord from its notes?
Select the notes on the keyboard or build the shape on the fretboard above. The identifier stacks the notes into thirds, works out which one behaves as the root, measures the intervals above it, and names the quality that interval pattern defines. You get the chord name, the inversion you are in, and the interval breakdown that produced the answer.
What chord is this? I only know the notes.
Notes are all you need — a chord is nothing more than a set of pitches. Enter them in any octave and any order; the tool identifies the chord from the pitch classes and uses your lowest note only to decide the inversion. C-E-G, G-C-E and E-G-C are all C major, in root position, second inversion and first inversion respectively.
Why do I get more than one answer?
Because a set of notes can be read from more than one root. A-C-E-G is Am7 read from A, but read from C it is C6 with A in the bass — the same four pitches. Both readings are shown, best match first. What decides the right name is context: the key you are in and the chord that came before.
How does the identifier tell an inversion from a different chord?
By the bass note. The chord tones fix the chord; the lowest sounding note fixes the inversion. If your lowest note is the 3rd, you are in first inversion and the chord is written as a slash chord — C/E. If it is the 5th, you are in second inversion: C/G. The tool names the parent chord and then tells you which inversion it is voiced in.
Does it work for guitar shapes?
Yes. The guitar tab gives you a six-string fretboard where each string can be muted, open, or fretted up to the 12th fret. It works out the sounding note of every string, so a shape you invented gets a real name — including which strings are doubling the root and which are adding the 7th.
What is the difference between this and the chord finder?
Nothing under the hood — the chord identifier and the chord finder run the same engine. This page leads with the question (you have notes and want a name) and explains the theory behind the answer; the chord finder page is the general-purpose tool with the same two inputs.