Root on A string
x-11-12-13-12-x
A♭dim is the A♭ diminished chord. Its notes are A♭, C♭ and E♭♭. It is the same chord as G♯dim. A compact, tense triad. Every interval in this voicing is a chord tone.
x-11-12-13-12-x
Numbers show frets from the low E string to the high e string; x means don't play that string.
A♭dim is the vii° chord in A major. That makes it a natural fit in songs written in those keys.
Every A♭, C♭ and E♭♭ on the first 12 frets. The filled dots are the root, A♭. Build your own shape from any nearby group.
Other A♭ chords
Other diminished chords