How do you trim audio as iPhone ringtone?

iPhone Ringtone Maker will preset a 40-second cutter to easily trim a long audio and save as ringtone (the segment will be highlighted. If the audio is less than 40 seconds, the the whole audio will be selected).

To trim the audio, simply drag the cutter to adjust the position. You can also use Left and Right key to do adjustment.

You can also manually define the ringtone length by dragging the left or right end of the highlighted segment, or by inputting time points in the Start Time and the End Time boxes. Here shortcuts are also supported. Press Option + Up Arrow to trim audio from the left edge, Option + Left Arrow to extend it from left, Option + Down Arrow to trim audio from the right, and Option + Right Arrow to extend from the right.

Note that you can always select the segment you want by holding down the mouse and dragging. The Trim Time shows the duration of the segment.