How to Rotate a Video on Mac

The fastest way to rotate a video on Mac is to select the file in the Finder and choose Rotate Left from the quick actions. Hold Option first and it becomes Rotate Right. Here's that, the QuickTime Player route for clips inside a longer movie, and why the clip was sideways to begin with.

Rotate a video on Mac in QuickTime Player

Open the movie, then choose View > Show Clips. This step trips people up: the rotation commands act on a clip, so until the clips view is open the Edit menu has nothing to offer. Select the clip you want , it picks up a yellow outline , then choose Rotate Left or Rotate Right from the Edit menu. Each command turns it 90 degrees, and four of the same command returns it to where it started. Click Done when it's upright.

Nothing has touched the file yet at that point. The rotation lives in the open document until you save it, which means a wrong turn costs one more menu command rather than a re-export.

For a whole file rather than a clip inside one, the Finder is faster: select it, choose Rotate Left from the quick actions, and repeat to keep turning. Holding Option switches the command to Rotate Right.

Orientation is metadata, and metadata disagrees

Rotation is nearly always a repair, not a creative choice, and the cause is usually the same one. The camera records which way the device was held; the playback app reads that and turns the picture to match. When orientation lock was on, or the device was held flat while it made up its mind, the recorded orientation and the actual framing disagree, and every player afterwards faithfully reproduces the disagreement.

Rotating fixes the metadata mismatch, not the framing. If the shot was composed sideways, standing it up gives you a correctly oriented clip that's still framed for the wrong shape, and the next step is a crop rather than another rotation.

A vertical frame has no wrong way up

Montaj works in a vertical 9:16 frame from the start, so orientation isn't something you discover at the end. What you're looking at while you cut is the shape the clip is going to be watched in, which removes the whole category of surprise where a finished edit turns out to be lying on its side.

That also changes what a rotation means. In a vertical frame there's no correct-but-wrongly-shaped result waiting at the end: a clip either fills the frame or it doesn't, and you can see which while there's still time to reframe it. Everything happens on your device, with nothing uploaded. If you just need to rotate a video on Mac and move on, the Finder already did it. This is for the clips you're building rather than repairing.