Will this change the format?

No. The resized file keeps the format MediaBunny read.

What if I set both width and height?

The picture fits inside that box without stretching.

Change the height or enter a custom size. The output stays in the same format, on your device.

Files stay on your device

Drop a video to resize

Choose a height or enter a custom size. The output stays in the same format.

Any media file this browser’s engine can read.

Supported inputs: Any media file this browser’s engine can read.
What happens: The picture is resized and saved in the format that was opened. Setting both width and height fits the picture inside that box.
Limits: A video track is required. Browser codec support and device memory affect export.