Use the Web Editor to crop the beginning and ends of your presentation. You can adjust the duration of the fades as needed.
To crop the beginning or end of a presentation:
1. Drag the timeline cursor to the new starting (or ending) point.
2. Adjust the fade-out position using the fade handles.
3. Click Undo or Redo to back out of changes as needed. Once you have completed your edits, save changes.