Avatar video aspect ratio for a Shorts series: 9:16, 1:1 or 3:4?
Avatar 1.0 renders 1:1, 3:4, 9:16, 4:3 and 16:9 (default 9:16) at 720p. YouTube Shorts series accept portrait or square only, so 4:3 and 16:9 are out for them.
Which aspect ratio should an avatar episode use for a YouTube Shorts series? Use 9:16 (the Avatar 1.0 default) for full-screen vertical, or 1:1 or 3:4 if you want a squarer frame; YouTube's series feature accepts portrait or square videos, so 4:3 and 16:9 do not fit. All of them render at 720p at this time.
YouTube's series help page says episodes are up to 180 seconds each, portrait or square, in playlists that contain only Shorts. The aspect ratio is the first thing that can disqualify a render.
The options
aspect_ratio is a top-level field on the talking-video request and on the preview create request. The docs list five values and a default.
| aspect_ratio | Orientation | Fits a Shorts series |
|---|---|---|
| 9:16 | Portrait (default) | Yes |
| 3:4 | Portrait | Yes |
| 1:1 | Square | Yes |
| 4:3 | Landscape | No |
| 16:9 | Landscape | No |
Pick by placement
9:16 gives the most vertical screen on Shorts, Reels and TikTok, and it is the field default, so you can leave it out. 1:1 is a safer crop if the same file will also sit in a feed. 3:4 is a middle choice with more headroom for a caption block than 1:1.
Because the aspect ratio is a structural field, changing it after you approve a preview needs a new preview. Decide before the lead's first still, not after.
Resolution and duration
Resolution is 720p. The duration window is 4-60 seconds per job, estimated from the script or video_inputs. A 3-minute Shorts episode therefore needs at least three jobs, cut together afterward.
Checklist
Set aspect_ratio explicitly in your config even when it is the default, so a future default change does not alter your series. Check each finished clip's size against the series rule before you upload.
Why placement decides it
A series is a set of episodes that share a feed, so mixed ratios look unfinished. Pick one ratio for the whole season on day one and set aspect_ratio on every talking-video call, because the default is 9:16 and a missing field silently picks it. Changing mid-season means re-rendering earlier episodes if you want them to match.
- 9:16 fills a phone screen and is the default.
- 1:1 works in feeds that crop, and in a Shorts series.
- 3:4 sits between them if you want more vertical room than a square.
A note on resolution
Avatar 1.0 renders at 720p regardless of the ratio you choose, and a talking video lasts between 4 and 60 seconds. YouTube allows Shorts up to 180 seconds, so a single avatar job never reaches the platform ceiling. If an episode needs more than 60 seconds, split it into two jobs and join them in a Timeline render.
Sources
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Written by Sume