D Ionian

The D Ionian mode — D E F# G A B C# — shown across the guitar neck.

Swipe the neck sideways to see the higher frets.

D Ionian is the major scale — same seven notes, same order. The mode name describes which chord you treat as home, not a different set of notes.

The tool shows this from its parent key, D major, with D marked as where Ionian begins, the same seven notes centered on D.