How the transposition works
Each chord is split into a root note, an optional bass note after a slash, and everything else: the quality, meaning major, minor, seventh, suspended, diminished or augmented. Only the root and the bass note move; the quality is copied across exactly as typed, so Dm7 stays a minor seventh wherever it lands and Cmaj7 stays a major seventh.
Reading a chord grid
Paste chords separated by spaces, one line per row of the song, the way they would appear above a lyric sheet or in a lead chart. Anything that is not a recognised chord, such as bar lines written as |, section labels like "Chorus", or lyrics sitting on their own line, is copied through unchanged, so the layout of the original grid stays intact after transposing.
Supported chord shapes
Major and minor triads, sevenths (7, maj7, m7), suspended chords (sus2, sus4), diminished and augmented chords, added notes (add9), sixths and ninths, and slash chords with a separate bass note such as G/B all transpose correctly, provided the chord starts with a root letter from A to G, with an optional sharp or flat straight after it.
Semitones versus a target key
Transposing by semitones is the more direct route once you already know the shift, for example moving a song down a tone for a singer (-2 semitones) or up a full step for a capo change. Transposing to a target key is useful when you only know the destination: the tool reads the root of the first chord in the grid, treats it as the current key, and works out the matching shift automatically.