Workflow
Turn a square video into a vertical short
Short answer
Take a 1:1 square video to a 9:16 vertical frame. The loss profile is completely different from a landscape source, which changes the right answer.
The decision that matters: Unlike 16:9, a square source cropped to 9:16 loses the sides but keeps roughly 56% of the frame - and padding costs only modest bars. Padding is usually the better trade here.
Step by step
Check what you actually have
Read the dimensions, ratio, duration and size off the file before deciding anything. Most bad exports come from assuming the source rather than looking at it.
Compare both options for a square source
Run 1080×1080 into a 1080×1920 canvas and see the bar thickness; then compare with the crop cost.
Crop if you chose to fill the frame
Filling the vertical frame from a square source means cutting the left and right edges - place the box where the subject actually is.
Limits to know
- Padding a square into 9:16 leaves visible bands; some feeds letterbox it further, doubling the effect.
- Cropping still discards the left and right edges, wherever you put the box.
Run the whole workflow in one place
Koldflux takes one source through checking, reframing, captions and export, and gives you a pack per platform.
Reviewed October 5, 2026 by the Koldflux team against the platform limits used by the linked tools.