AI video resizer: landscape to vertical with the subject kept in frame

The aspect-ratio problem, solved once

A camera records in 16:9. TikTok, Reels and Shorts want 9:16. The Instagram feed prefers 4:5 or 1:1. LinkedIn and X will show a landscape video but give far more screen to a vertical one. If you post the same recording everywhere, you resize it four times — and the naive way, a centre crop, cuts the speaker in half the moment they lean left.

An AI video resizer solves this by finding the subject before it crops. Splicora detects faces and motion, then moves a vertical window across the original frame so the important part stays visible. The output looks like it was shot vertical, not squeezed into it.

When to use tracking and when not to

• One speaker, static camera — tracking keeps the face centred as they move; a fixed crop also works if they barely move.
• Two speakers or a panel — tracking follows whoever is active; for a split-screen look, open the clip in the editor instead.
• Screen recordings and slides — turn tracking off so the crop stays on the content rather than a cursor.
• Product shots and B-roll — tracking follows motion, which is usually what you want for a moving subject.

Resize is built into the whole pipeline

You rarely need to run the resizer by hand. Every clip the AI clip generator cuts is reframed to 9:16 automatically with tracking on, and the Reels generator and Shorts maker use the same engine. The standalone tool is for a video you already have — a finished landscape edit that now needs a vertical version.

Once resized, the clip is one click from captions, a hook and the scheduler.

Use cases, by platform

• TikTok, Reels and Shorts (9:16) — a podcast episode recorded in 16:9 becomes a set of vertical clips with the speaker centred; the clip generator runs this automatically.
• Instagram feed (4:5 and 1:1) — the same clip at a taller crop for the feed, where a vertical video is cut off, and square for a carousel cover.
• LinkedIn and X — both accept landscape, but a 4:5 or 1:1 version takes up to twice the screen in the feed and holds attention longer.
• Facebook — 4:5 for the feed, 9:16 for Reels and Stories.

Selecting several targets at once is the normal case: one run, three exports, each named for its platform, each one click from the scheduler.

Mistakes the resizer avoids

A centre crop cuts off whoever sits at the edge of a two-shot. A static crop follows nobody, so a speaker who leans out of the window leaves half a face on screen. A crop that jumps every time the subject moves is worse than either. Splicora tracks the subject and moves the window smoothly, holding still when the speaker is still and easing across when they move, so the reframed clip looks shot that way rather than cut down.

It also keeps on-screen text in mind: captions are added after the reframe, positioned inside the new frame by the subtitle generator, so nothing important is cropped by the platform's own interface.