ScreenFlow User Guide | Main Window : Timeline — Changing Clip Speed
| Changing Clip Speed You can change the playout speed of a clip by alt-clicking on the clip near the beginning or end of the clip. When you do this, the Mouse Pointer will change to to indicate you can change the speed. Alt-click and drag out to speed up the clip or drag in to slow it down. You can also change the playout speed in the Clip Inspector. A clip that has been slowed down will be marked with a , a speeded-up clip with a .