# Should an AI drama be vertical (9:16) or horizontal (16:9)?

**Short answer:** Vertical 9:16 for short dramas watched in phone feeds and short-drama apps; horizontal 16:9 for films and long-form YouTube. Compose for the target from the first frame, because cropping 16:9 to 9:16 keeps only about a third of the picture.

URL: https://arc.katechon.technology/answers/vertical-or-horizontal-for-ai-drama
Updated: 2026-10-18

## Pick by where it will be watched

Which aspect ratio for which release:

| Release | Aspect | Our example |
| --- | --- | --- |
| Short-drama apps, TikTok, Reels, Shorts | 9:16 | [Blood Sun: The Fall of Kratos](https://arc.katechon.technology/films/blood-sun), [High Note](https://arc.katechon.technology/films/high-note) |
| Long-form YouTube film or feature | 16:9 | [The Fall of Kalak](https://arc.katechon.technology/films/the-fall-of-kalak), [The Wolf Mother](https://arc.katechon.technology/films/the-wolf-mother) |
| A widescreen trailer or opening of a vertical series | 16:9 | [The Emperor's Pleasure Court](https://arc.katechon.technology/films/the-emperors-pleasure-court) |

## Why not crop later

A 9:16 frame cut from a 16:9 frame at the same height keeps 9/16 of 9/16 of the width, about 32% of it. Faces drift out of frame and two-shots become one-shots. Generating natively in 9:16 composes every reference, storyboard and clip for the phone.

## Making both

For [The Emperor's Pleasure Court](https://arc.katechon.technology/films/the-emperors-pleasure-court) we remade the opening of a vertical series in 16:9: 55 script units, the same cast sheets, and every location re-shot as 16:9 camera plates so the widescreen film matched the vertical episodes. Reusing characters is cheap; locations need new framing.

## What changes in the writing

- Vertical: more close-ups and two-shots, one subject per frame, action stacked top to bottom.
- Horizontal: room for wide establishing shots, groups and movement across the frame.
- Captions: centred low in vertical; standard subtitle position in horizontal.
- Platform rules: TikTok's Drama Center required derivative materials such as trailers to be 9:16 and at least 1080p when we submitted ours, so a 720p vertical master needed upscaling for those.

## Where Katechon Arc fits

Arc projects are set to 9:16 or 16:9 and compose references, storyboards and clips for that frame.

Arc has no other aspect ratios such as 1:1 or 4:5, and does not reframe a finished film automatically.

## Related answers

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- [What is the best AI video generator for TikTok and YouTube Shorts?](https://arc.katechon.technology/answers/best-ai-video-generator-for-tiktok-and-youtube-shorts): Choose one that composes natively in 9:16 rather than cropping a widescreen render, keeps your characters consistent across posts, and has…
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