How can I rotate a video? I just recorded a video on my phone, but when I play it on my Mac it's in the wrong orientation. 

How can I rotate the video by 90 degrees so that I can upload it to youtube?

Free solutions are preferred.



I just found out how to do it using YouTube's Video Editor which has rotate left/right buttons. 

But this is not an answer how to rotate on Mac.
Use QuickTime to Rotate Videos
You don't need to use any 3rd party tools to do this. It's built right in to QuickTime Player.
Any file that can be opened in QuickTime can be rotated by choosing Edit &gt; Rotate Left (or Right) or by typing Command-Shift-L / R.
If you alter a movie file in this way and attempt to close the file (Command-W) you will be prompted to save your changes. Save them to a new file and you will have a newly rotated video.
Share your Video on YouTube with QuickTime
QuickTime also has a built-in way to share your video on YouTube. With the video open (and correctly rotated now) select Share &gt; YouTube...