How to resize a video
Two settings under Output control the size and shape of the exported file. They do different things and combine.
Size
Size sets the short side of the output: 1080, 720, 480 or 360. The long side follows the shape. It never scales up: a 720p clip set to 1080 stays 720p.
Use it to make a file smaller, or to match a platform's limit. 1080 is what Instagram, TikTok and YouTube expect; 720 halves the file for a message or a preview.
Format
Format sets the shape: 9:16 for Reels, TikTok, Shorts and Stories; 1:1 for a square feed post; 16:9 for YouTube and a TV. What happens to a clip whose shape does not match depends on whether you crop.
- Without a crop, the whole picture is placed inside the new shape and the remaining space is filled. With Blur fill on, which is the default, the bars are a blurred copy of the video; off, they are black. Nothing is cut away.
- With a crop on, the crop box takes the format's shape and keeps it while you drag, so the output is a real cut to 9:16 or 1:1 with no bars. Press C, drag the box over the subject, and export. See how to crop a video.
The preview switches to the output shape as soon as you pick a format, so you see exactly what will be exported. The Preview drop-down puts a phone frame around it, with the Story, Reels or Shorts overlay in the right place.
Which to choose
- One subject in the middle of a wide shot: crop to 9:16.
- A landscape, a group, text on screen: keep it all with blur fill.
- A vertical clip for YouTube: 16:9 with blur fill. Cutting it down to a band loses most of the picture.
Apply to all
Set size and format on one clip and press A. Every clip in the list gets the same size, format, rotation, mirror, crop and colour. Trims stay per clip.
Questions
Does resizing lose quality?
Scaling down and adding bars both re-encode the clip once, at a high quality setting. The picture inside is never scaled up.
What size does 9:16 give me from a 1080p landscape clip?
Cut: 608 by 1080, the full height of the source. With blur fill: 1080 by 1920, the picture in the middle at 1080 wide.
Is there a faster way for just one clip?
The small pages landscape to portrait and portrait to landscape do only this, and work on a phone.