Add a movie or clip in QuickTime Player on Mac
You can add whole movies or clips from other movies to your movie.
Add an entire movie
In the QuickTime Player app
on your Mac, open the movie you want to add to, then choose View > Show Clips.Do one of the following:
Insert the clip at the end of the movie: Without selecting any clips, choose Edit > Add Clip to End.
Insert the clip at the beginning of the movie: Without selecting any clips, press Option, then choose Edit > Add Clip to Beginning.
Insert the clip elsewhere in the movie: Select a clip, then choose Edit > Insert Clip After Selection.
Find and select the movie you want to add to your movie, then click “Choose media.”
Add a new clip
In the QuickTime Player app
on your Mac, open the movie that contains the clip you want to add. Choose View > Show Clips.
Select the clip, then choose Edit > Copy.
The selected clip is outlined in yellow.
Open the movie that you want to add the clip to, then choose View > Show Clips.
Choose Edit > Paste.
The clip appears at the beginning of the movie. Drag the clip to rearrange it.