Turn Horizontal Video into Vertical: Crop for Mobile Screens
Vertical feeds dominate mobile: Douyin, Channels, and Shorts are 9:16. Letterboxing a horizontal video shrinks the subject to a thin strip. The right move is cropping: keep the vertical band where your subject lives and let the content fill the screen.
Decide where the subject is before cropping
Going 16:9 to 9:16 means giving up about two-thirds of the width — where you crop is a composition decision. Centered talking heads crop symmetrically; off-center subjects shift the crop toward them; keep captions inside the safe area.
How much to cut: the 9:16 math
A 1080p horizontal frame (1920×1080) keeps roughly 608 pixels of width at 9:16 — about 34% off each side. The crop tool takes percentages per edge (0-45% each), so 34% left and 34% right lands the vertical band exactly.
- Full-frame talking head: crop 34% each side
- Off-center subject: shift the crop so the subject sits mid-frame
- Edge-hugging captions: check their position first
Resize after cropping?
The crop tool cuts pixels and never scales; the resize tool scales proportionally to a target height and never crops. Crop first, then resize if you need a unified output spec — the order never reverses. Everything runs locally in the browser.