Why does it write E sharp instead of F?

Because that is the correct name of that note in that chord. A chord tone's letter is the root's letter advanced by its degree: a third is two letters up, a seventh is six. The third of C sharp is therefore some kind of E, and the pitch it lands on is the one usually called F, so in a C sharp chord it is written E sharp. Reading it as F would spell the chord as a root, a fourth and a fifth, a sus4 chord's spelling attached to a sound that plainly has a third, which is not how anyone writes or reads harmony. The finder spells every note this way, from the degrees, rather than from a fixed table.

Free Online Chord Finder: Tap Notes, Get the Chord Name

What this chord finder does

Most chord tools go from a name to a shape: you ask for G7 and they show you where to put your fingers. This one goes the other way, from the notes to the name, which is the question that actually comes up in practice. You worked out a song by ear and want to write the chords down. You moved one finger in a shape you know and it sounds wonderful and you would like to find it again. You are reading a piano part and want to know what the left hand is doing. Enter the notes and the finder tells you, in the same words a musician would use, and the guide to how chords work explains why those words mean what they mean.

How to use it

Choose the instrument. The guitar is a twelve-fret neck in standard tuning, high E at the top the way a chord diagram reads. The piano is two octaves; move the lowest octave up or down to reach the register you play in.

Tap the notes. Every note you tap is added to the set and shown as a chip under the instrument, spelled correctly for the chord it turns out to be in, with its degree beside it (R for the root, 3, 5, ♭7 and so on). On the guitar, every other place that same note lives on the neck is ringed, so you can see the shape's cousins up the fretboard.

Read the name. One note is just a note. Two notes are named as an interval (or a power chord, if that is what they are). From three notes up, the finder searches its dictionary of thirty-eight chord types from every possible root and gives you the best reading, with the others it considered listed under "could also be". Tap an alternative to read its description.

Hear it. The Hear It button plays your notes one at a time from the bass upwards, then all together, so a chord you assembled by eye can be checked by ear. That one-at-a-time playing is an arpeggio, and it is also the way the app's Chord Finder listens.

The rules it names by

The bass note decides. C, E, G and A are C6 when C is the lowest note and Am7 when A is. Same four notes, two correct names, and the one a musician would use depends on what is underneath. That is why the finder works with real notes in real octaves rather than a bag of letter names, and why moving your lowest note can change the answer. The reading it did not pick is still offered, written as a slash chord (Am7/C) when its root is not in the bass.

Spelling follows the degrees. A chord tone's letter is the root's letter advanced by its degree, and its accidental is whatever closes the gap to the actual pitch. So the third of C♯ is E♯, the seventh of D♭7 is C♭, and the doubly-flattened seventh of Bdim7 is A♭. The chips under the instrument show these spellings, and their octave numbers follow the letter as well: the C♭ in a D♭7 chord played at the pitch B3 is written C♭4, because scientific pitch notation numbers the letter, not the key on the piano.

Simple beats complex, complete beats incomplete. When two chord types both explain the notes, the plainer name wins; a root in the bass beats a slash chord; and a chord with all its notes present beats one that has to assume a missing fifth. A dominant or minor seventh chord played without its fifth, the everyday guitar voicing, is still named and marked (no 5), because the third and the seventh carry that chord. Triads and suspensions never lose their fifth, since dropping it leaves a set some other reading explains better.

Nothing is guessed at. A set the dictionary cannot explain in full is shown as its intervals from the bass rather than forced into the nearest name. An honest "no name for this" is more useful than a confident wrong one, and some of the best sounds on a guitar are exactly those sets.

Try it with the shapes you already know. Tap the open C shape (E2 open is not in it; start at C3 on the A string, then E3, G3, C4, E4) and read the chips. Now move the C4 on the B string up one fret to C♯4 and see what the finder calls it. Then take the C4 away altogether. Each of those is a chord you can use tonight.

Chord finder, chord identifier, reverse chord finder

People search for this tool under a lot of names: chord finder, chord identifier, chord namer, reverse chord finder, "what chord is this", "what chord am I playing", guitar chord finder, piano chord finder. They are all the same question, notes in and a name out, and this page answers it for both instruments. If what you wanted was the other direction, a chord chart from a name, the alternatives row is a decent start (tap Am7, read C6/A, and you have learned a substitution), but the real answer to that is a chord book, and the real answer to understanding either direction is the guide to chords on the blog.

Who uses one

Player	What the finder is for
Guitarists	Naming a shape you found by feel, writing a song down, working out which extension a voicing is, seeing the same chord all over the neck
Pianists and keyboard players	Naming what the left hand is doing, checking a voicing against a lead sheet, learning why C6 and Am7 share notes
Bassists	Seeing which chord tone you are on, and how your choice of note changes the chord's name (that is the slash chord)
Singers and choir members	Finding the chord under a harmony line so the part makes sense instead of being a list of notes
Songwriters and producers	Naming the chords in a progression so it can be written down, transposed, and played by someone else
Music students and teachers	Checking spelling and inversions, drilling the seventh chords, seeing the alternatives a set of notes allows
Drummers	Yes, drummers: knowing where the changes are is how you play the form, and naming the chords in the tune you are learning is the fastest way to hear them

The engine behind it

The dictionary and the naming rules on this page are a direct port of ChordTheory from the Metro Gnome app, the same pure music-theory core that names chords on the phone. Chord types are defined by degrees ("1 ♭3 5 ♭7"), not by semitone offsets, which is what makes the spelling come out right; every candidate root is tried against every type; and the ranking is a plain score (complexity, plus a penalty for a slash reading, plus a larger one for an assumed missing fifth). The app's test suite proves the dictionary has no two types sharing a set of notes and that every type survives a round trip through the namer. Porting it rather than rewriting it means the browser and the phone can never disagree about a chord.

Questions about chord finders

What is a chord finder?

A chord finder, sometimes called a reverse chord finder or chord identifier, works backwards from the notes to the name. You tell it which notes you are playing, on a guitar fretboard or a piano keyboard, and it tells you what chord that is: C major, Am7, G7 with no fifth, Dm7♭5 over A♭. A chord chart works the other way, from a name to a shape. This tool is the first kind.

How does it decide between two names for the same notes?

The lowest note decides. C, E, G and A are C6 when C is the lowest note and Am7 when A is, which is exactly how a musician would name them, so the finder needs real notes with octaves rather than just letter names. The reading it did not choose is still shown as an alternative, written as a slash chord if its root is not the bass. Simpler names also win over more complex ones when both explain the notes.

Why does it write E♯ instead of F?

Because that is the correct name of that note in that chord. A chord tone's letter is the root's letter advanced by its degree: a third is two letters up, a seventh is six. The third of C♯ is therefore some kind of E, and the pitch it lands on is the one usually called F, so in a C♯ chord it is written E♯. Reading it as F would spell the chord as a root, a fourth and a fifth, a sus4 chord's spelling attached to a sound that plainly has a third, which is not how anyone writes or reads harmony. The finder spells every note this way, from the degrees, rather than from a fixed table.

Can it hear a chord through the microphone?

This page cannot; you tap the notes in. The Chord Finder in the Metro Gnome app can: play the chord one note at a time, as an arpeggio, and the app's tuner engine captures each note as it settles and names the chord from what it heard. It listens for single notes deliberately, because a strummed chord has no single pitch for a tuner to find, and the arpeggio path is the one that gives an honest, exact answer.

What chords does it know?

Power chords, major, minor, diminished and augmented triads, sus2 and sus4, sixths, added ninths and six-nine, every common seventh (major seventh, dominant seventh, minor seventh, minor-major seventh, diminished seventh, half-diminished, seventh suspended, augmented and flat-five sevenths), ninths including the ♭9, ♯9 and ♯11 colours, and elevenths and thirteenths: thirty-eight chord types. A dominant or minor seventh played without its fifth, the everyday guitar voicing, is still named, marked (no 5). Two notes are named as an interval, and a set the dictionary cannot explain in full is shown by its intervals from the bass rather than given a wrong name.

Is this chord finder free?

Yes. It runs entirely in your browser with no download, no account and no payment, and it uses the same chord dictionary and naming rules as the Chord Finder in the Metro Gnome Android app, which is also free.

The same finder, with ears, on your phone.

Metro Gnome's Chords tab does everything on this page and one thing more: play the chord as an arpeggio and it names what it hears, using the same pitch engine as its tuner. It sits beside a drift-free metronome to practise your changes over, a chromatic tuner to get the guitar right first, and a tuning drone to hear each chord tone against its root. Free on Android, no account, no subscription.

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Use this on your own site

This chord finder embeds on any website with one line of HTML, free, with no sign up and no API key. Guitar teachers, piano teachers, theory pages and songwriting forums are welcome to put it straight onto a lesson page. Get the embed code.

What this chord finder does

How to use it

The rules it names by

Chord finder, chord identifier, reverse chord finder

Who uses one

The engine behind it

Questions about chord finders

The same finder, with ears, on your phone.

Use this on your own site

Also useful