You will often seen chord symbols like this:

CMa7/E  and   CMa7/D

The first is an inverted chord and the second is a "slash chord".   FastChords allows you to enter both types of chords.  But how can you tell an inverted chord from a slash chord?

Simple.  If the chord is not and inverted chord, then it is a slash chord ...

No.  Seriously, the note following the slash ("/"), called the bass note,  if it is one of the chord notes, then the chord is an inverted chord, otherwise the chord is a slash chord.

A quick way to tell is to do all the chord inversions with the INV button.

Step 1: produce the CMa7 chord.

CMa7

original chord

(the chord root note is also the bass note)

Step 2: click on the INV button

CMa7/E

first inversion

(notice where the original root note lands, the E note is now the bass note)

Step 3: click on the INV button

CMa7/G

second inversion

(the G note is now the bass note)

Step 4: click on the INV button

CMa7/B

third inversion

(the B note is now the bass note)

Step 5: click on the INV button

CMa7

original chord

(the chord root note is once again the bass note.  The whole chord is now one octave above the original keyboard position)

In the above example, since none of the chord inversions produced the D note as the bass note, then we conclude that the CMa7/D chord is a slash chord instead of an inverted chord.  Conversely, since the E note did appear as a bass note, we conclude that the CMa7/E chord is an inverted chord.