The IndiPiano Chord Dictionary is a free online chord finder and music theory reference that lets you look up, see and hear 950+ different chord and key combinations across all 12 root keys, with no login and no download. Pick a root key and a chord type, and the tool instantly spells every note of the chord, shows its formula and interval labels, highlights the notes on a piano keyboard or a guitar fretboard, and plays it back as a strummed block chord or an arpeggio, so you learn how each chord looks, fingers and sounds.

950+ Chord and Key Combinations Across Six Families

The library covers a wide variety of chord families: basic triads and suspended chords, seventh chords, sixth and added-tone chords, extended chords (9th, 11th and 13th), altered and jazz dominants, and exotic, modal and modern chords. Sizes range from simple 3-note triads to 6-note and 7-note extended and altered voicings. The collection includes major, minor, diminished and augmented triads, sus2 and sus4 chords, dominant, major and minor sevenths, half-diminished and diminished sevenths, 7alt, 7♯9 and 7♭9 dominants, quartal and quintal stacks, the Tristan chord, the Mystic chord, and the Italian, German and French augmented sixths. You can search by chord name, symbol, alternate name or use.

Correct Spelling and Interval Labels

Every chord is spelled with proper theory note names, so you see the right letters for each key instead of a random mix of sharps and flats. You can leave the accidentals on Auto or force sharps, flats or the common mixed spelling. Intervals are labelled the way musicians read them, including compound intervals such as ♭9, 11 and 13, and chord symbols are shown in the standard notation along with alternate names. Nicknames and look-alike chords are listed as related names rather than strict aliases, with short notes explaining where two chords share the same pitches but differ in spelling and function, as with the dominant 7th and the German augmented sixth.

Piano Layout and Studio-Style Playback

The piano tab highlights the chord tones and marks the root, and every key can be pressed to hear it. Playback can strum the chord as a block or arpeggiate it upward, downward or up and down, at slow, normal or fast tempo, while each note flashes on the keyboard. The sound engine is built in the browser with the Web Audio API and offers three synthesised instruments: piano, harmonium and an acoustic guitar modelled with Karplus-Strong plucked-string synthesis. Arpeggios always follow true pitch order, so the notes rise and fall exactly as they would on a real instrument.

Guitar Layout with CAGED Chord Shapes

The guitar tab draws a full fretboard in standard tuning with fret numbers, open strings and note names. Each chord is shown as up to five playable positions built from the C, A, G, E and D shapes of the CAGED system, numbered from the lowest fret upward, with the familiar open shapes used where they exist. Behind it, a voicing generator checks every shape against the chord formula, keeps the defining tones such as the 3rd, the 7th and the top extension, and limits each shape to four fingers with a single barre. Across the library it produces thousands of verified fretboard shapes. When a large chord drops a tone to stay playable, the omitted degrees and note names are listed under the fretboard, and numbers on the board are chord degrees, not finger numbers.

Inversions and Slash Chords

An inversion panel shows each chord in root position and in its 1st, 2nd and 3rd inversions where the chord has enough notes, labelled with its bass note, and you can click any voicing to hear it. This makes it easy to hear how the bass note changes the colour of the same chord and to plan smooth voice leading between chords.

Built for Every Screen

The tool is a single lightweight web app written in plain HTML, CSS and JavaScript with no external libraries. It is fully responsive: the layout, keyboard, fretboard and dropdowns resize to suit phones, tablets and desktops, and it works in modern browsers. Use it to learn chords, build progressions, write songs, study jazz harmony, compare voicings or practise ear training, whether you play piano, guitar, keyboard or sing.