Change Video Aspect Ratio with FFmpeg

How to fix an incorrect video aspect ratio using the FFmpeg command-line tool.

Oct 22, 2025 ffmpeg, cli 1 min read

For some reason, a few of the video files I’ve received or downloaded from the internet have the wrong aspect ratio.

For example, a video that’s supposed to be vertical (9:16) might play as a widescreen video (16:9).

Not in the mood for reading? Watch the video instead.

The video content itself is probably fine. It’s likely that some of its metadata was saved incorrectly when it was edited.

You can fix this easily with ffmpeg. Let’s assume your incorrect video file is named input.mp4. Just run the following command:

ffmpeg -i input.mp4 -c copy -aspect 9:16 output.mp4

Once it’s done, open the output.mp4 file. It should now display the video with the correct aspect ratio.

I hope this simple tutorial helps solve your problem!

As usual, if you have any questions or a better method, leave a comment below. Thanks for reading, and see you next time!