Why videos end up sideways
Phones and cameras record the picture in the sensor's native direction and often add a note saying how the video should be turned when played. Some players respect that note and others ignore it, which is why a clip can look correct on one device and sideways on another. Footage that was filmed with the camera held at an angle, or exported by software that dropped the note, can also arrive rotated.
Rotating a video means turning every frame by a fixed amount, here 90, 180 or 270 degrees. A quarter turn also swaps the dimensions: a video that was 1920 by 1080 becomes 1080 by 1920 after a 90 degree turn.
This tool performs a true rotation of the picture itself, not a playback hint, so the result looks the same everywhere.
When you need to rotate a clip
The usual case is a clip that plays on its side or upside down. Another is a landscape recording you want to present as portrait, or the reverse, for a particular screen. A clip that was flipped by mounting a camera upside down needs a 180 degree turn.
Rotating is not the same as mirroring. A rotation keeps the picture the right way round, only turned. If your text appears backward, you need a flip, which this tool does not offer.
Since every frame is rewritten, rotation re-encodes the video. That means it takes longer than just relabeling the file, and the output is a fresh encode rather than an exact copy of your original data.
How to rotate a video with this tool
- Drop a video file onto the upload area, or click to choose one.
- Pick a rotation using the buttons: 90°, 180° or 270°. The 90° button is selected when the file first loads.
- Click Run. The first time, the video engine downloads (roughly 30MB) and is cached afterward.
- Wait for the progress bar to finish, then check the preview player.
- Click Download to save an MP4 named after your original file followed by
-rotate.
The three buttons work like this: 90° turns the picture clockwise by a quarter, 180° turns it upside down, and 270° turns it a quarter the other way (the same as 90° counterclockwise). There is no live preview of the rotation before you click Run, so if the result is turned the wrong way, choose the opposite button and run again from the original file.
Tips and limits
If a clip is sideways, work out which direction fixes it first. A clip lying on its left side needs one quarter turn and a clip lying on its right side needs the other. Picking wrong costs you a second run, which can be slow for long videos.
Only the three fixed angles are available. Small corrections such as straightening a tilted horizon by a few degrees are not possible here.
The output is always an MP4 with default encoder settings, and there is no quality control. Large or long videos are processed in browser memory and may be slow or fail if the device runs short, in which case the tool shows an error message. Running the rotation on the original file each time is better than rotating an already rotated result, because each encode costs a little quality.
For related jobs, the Crop Video tool trims the edges of the frame, and Mute Video removes the sound track.