How to convert horizontal video to vertical and keep the subject

How do you convert 16:9 to 9:16?

Make a vertical project, put the horizontal footage in it, and choose how to fill the frame. There are four ways, and only one of them works for most videos:

Reframing is what "auto reframe video" tools do: they find the subject and move the crop for you. A blurred background is the fallback for shots with no single subject, such as a landscape or a slide. Video aspect ratios explained covers the shapes themselves.

How much of the picture does a vertical crop keep?

Less than a third of the width. A 9:16 window cut from a 16:9 frame of the same height is 31.6% as wide, so 68% of the picture goes. Two things follow:

• Resolution. From 4K (3840 × 2160), the vertical slice is about 1215 × 2160, more than enough for a 1080 × 1920 short. From 1080p, the slice is about 608 × 1080 and has to be enlarged by 1.78 times, which softens it. Shoot 4K if you know a vertical cut is coming.
• Movement. Anyone who moves more than a little leaves a fixed crop. An ear in shot and a face out of it is the classic centre-crop mistake.

What are the framing rules for 9:16?

• Eyes about a third from the top. The same headroom as in a wide shot, scaled to the tall frame.
• Room in the direction they look. A person looking left needs space on the left, even in a narrow frame.
• Words clear of the apps. TikTok, Reels and Shorts put buttons down the right and a description along the bottom. Keep faces, captions and titles out of those strips; turning a long video into shorts gives the measurements.
• Slow, deliberate moves. A crop that chases every head turn makes viewers seasick. Hold still, and move only when the subject does.
• One subject at a time. When two people talk across a wide frame, cut between them rather than squeezing both in.

How do you keyframe the crop by hand?

In any editor that keys its crop, the method is the same: set a key where the subject is, move the playhead to where they have moved, shift the crop, and let the editor glide between the two. In Sharpy:

1. Decide the shape first. Choose File, then Decide the Finished Piece, and give 9:16, a size such as 1080 × 1920, or a destination by name. Framing waits for the decided shape, so set it before you start.
2. Crop on the picture. Drag the edges and corners in the viewer; the part cut away is dimmed while you drag, and the crop snaps to the 80% and 90% safe areas.
3. Key the crop. Click the diamond beside the crop sliders to set a key, then move the playhead and drag the crop again: each change sets a new key. Cropping in over a shot is a push in; moving the kept part across is a pan.
4. Ease the move. Give the keys a curve, such as ease in and out, so the pan starts and stops gently instead of at a constant speed.

How does Sharpy convert a horizontal video to vertical?

It reframes for you, and asks before it decides the shape. Sharpy never guesses the finished size: until you decide it, the viewer shows the recording's own shape and says so. Once you have chosen 9:16:

• Every clip is reframed around its own subject, because people rarely stand in the middle of the frame. It fills the vertical frame from a wide shot on the person, keeps headroom line by line as they move, and frames a shot with no face on where the eye is drawn.
• The speaker is held in place. Following keeps a speaker where they are on the first frame and takes out the wandering from the rest; to put them elsewhere, move them with the crop.
• Captions and graphics stay clear. On a vertical piece, captions keep off faces, and the words in captions and graphics are held clear of the platform's buttons.
• Every shape comes from one edit. The export panel's destinations set shape, codec and loudness together, so a vertical cut cannot go out at 1920 × 1080: vertical renders 1080 × 1920 and square 1080 × 1080, each at −14 LUFS. You can queue several shapes and destinations at once.

The shorts guide has a measured test of Sharpy's reframe against a plain centre crop. For a blurred background, lay the clip on a track beneath, enlarge it and give it a blur; animated captions then go over the top.

Can CapCut make a horizontal video vertical?

Yes. CapCut's own guide describes an Auto reframe tool on its desktop app that takes a horizontal video, lets you pick a vertical frame such as 9:16 or 3:4, and keeps the main subject in frame, with settings for stabilisation and camera speed. Check each shot afterwards: any automatic reframe can lose a second subject or cut through a gesture.

Sources

Checked on 18 October 2026.

• CapCut: How to make a horizontal video vertical
• TikTok Ads: video ads specifications
• YouTube Help: upload YouTube Shorts