Turn a sideways or upside down clip upright, or mirror a selfie recording so text reads the right way. Pick a turn and a flip, check the preview, and export.
Rotation flag vs re-encode
A phone does not rotate the pixels when you film in portrait. It records the sensor’s landscape frames and writes a rotation value into the MP4 or MOV header, and the player turns the picture on playback. That value is why a clip can look correct on the phone and sideways in an editor that ignores it.
- Rotation flag adds your turn to the value already in the header and copies the video packets untouched. No generation loss, and a long recording exports in seconds. Available for MP4 and MOV files in H.264 or HEVC.
- Re-encode decodes each frame, draws it turned and mirrored, and encodes it again at a high bitrate. The result plays upright in every player because the pixels themselves are upright.
Use the flag first. If the result still plays sideways in the place it has to work, export again with Re-encode.
Flips
Flip horizontal mirrors the picture left to right, which undoes the mirror some front cameras apply. Flip vertical turns it top to bottom. A 180° turn is a vertical flip plus a horizontal one. Text in a turned clip reads upside down; in a vertically flipped clip it reads upside down and mirrored.
Flips apply to the picture as it will play, after the turn, so “horizontal” always means the output’s horizontal. Neither container family has a mirror flag, so any flip re-encodes.
Output size
A 90° turn swaps width and height: a 1920 × 1080 clip becomes 1080 × 1920. When re-encoding, the resolution cap limits the long edge and never scales a frame up, and both sides are rounded to even numbers because H.264 requires it. The Output panel shows the exact size before you export.
Audio
The soundtrack is copied when the container allows it and re-encoded when it does not. Choose Remove audio for a silent file.