YouTube Shorts aspect ratio: what YouTube states and what to export

What YouTube states, as of 11 October 2026

Every figure below is read from YouTube's own help pages on 11 October 2026. We only list what YouTube prints. Where the pages are silent, the next section says so.

What YouTube does not state

The pages we read name 9:16 in only one place, a note that vertical videos on computer browsers may get extra padding. No page says 9:16 is required, and none gives a pixel size for vertical video. The resolution table lists 1080p as 1920x1080 for the default 16:9 ratio only.

• No exact ratio such as 9:16 or 1:1 is set as a requirement.
• No pixel size for vertical video, such as 1080x1920, is printed.
• No safe-zone margins for captions are given in the help pages we read.
• No minimum resolution for Shorts is given.

Ratios compared: 9:16, 1:1 and 16:9

That answers the search for a horizontal Short: a 16:9 file is not classed as a Short, however short it is. The rule applies to standard channels from 15 October 2024; videos uploaded before then stay long-form. Official Artist Channels have a later date, 8 December 2025.

Do not letterbox a wide video into a vertical frame

A common shortcut is to place the 16:9 picture in the middle of a tall canvas and fill the rest with black or a blur. YouTube advises against baking padding or black bars into the file, because they interfere with the player resizing to the video and the device. It also warns that vertical video on computer browsers may get padding of its own, white by default and dark gray in Dark theme. That padding is added by the player and is not something to design around.

Turning a 16:9 interview into 9:16

The arithmetic is simple. A 1920x1080 frame is 1080 pixels tall, so a full-height 9:16 crop is 607.5 pixels wide, about 32% of the frame. In a wide shot of two people sitting side by side, that crop holds one person at a time, and it is then scaled up roughly 1.78 times to reach 1080x1920.

KeyMo always outputs vertical 9:16 clips at 1080x1920, 30 fps, H.264/AAC, never 16:9. It tracks the face automatically when it reframes. The size matches the 1080p ceiling YouTube states, and the resolution page explains what that ceiling means. To test a custom crop first, use the aspect ratio calculator.

Using the same file for TikTok and Reels

A 9:16 export travels well. Instagram Help says Reels can be uploaded anywhere from 1.91:1 to 9:16, and TikTok's ad guidance tells advertisers to orient vertically at 9:16. Those are Instagram's organic upload range and TikTok's advice for ads, so read each platform's page for its own rules: TikTok size and Reels ratio.