K · PLATFORM & METADATA
Aspect ratio
The shape of the frame — and why it has to match the platform.
By Thomas Linck, founder · Updated June 2026
Aspect ratio is the width-to-height shape of the frame. 16:9 is the YouTube standard, 9:16 fills Shorts, TikTok and Reels, and 1:1 or 4:5 suit feed posts. The wrong ratio gets letterboxed or auto-cropped, and on a vertical platform it wastes most of the screen.
WHY IT MATTERS
A 16:9 clip dropped into a vertical feed shrinks to a thin strip with dead space above and below; a 9:16 clip on a TV gets two black pillars. Same footage, wrong container, worse video. Frame for the destination — and if one shoot feeds several platforms, compose with safe margins so both crops keep the subject.
TARGET · STANDARD
| YouTube (main feed) | 16:9 | TVs, laptops, embeds |
| Shorts · TikTok · Reels | 9:16 | full-screen portrait feeds |
| Feed posts | 1:1 / 4:5 | square and portrait placements |
How CutScore measures it
CutScore reads the aspect ratio of your file against the platform you are targeting, watches whether the subject stays inside the frame through the cut, and flags a mismatch or a drifting crop with the timestamp — before the feed letterboxes it for you.
QUESTIONS
Frequently asked.
You can, but it gets letterboxed into a thin strip with dead space above and below, and it reads as a re-post. If the clip lives on TikTok, reframe it to 9:16 so it fills the screen.
Shoot wide, keep the subject and text inside a centered 9:16 column, and export a reframed file per platform. No single ratio looks great everywhere, so frame for the worst-case crop.