Wan 3.0 defaults to adaptive before naming six shapes

The reference lists adaptive as the default and then 21:9, 16:9, 4:3, 1:1, 3:4 and 9:16. A request that says nothing about shape gets a shape the model picked, which is the opposite of how the other explicit row in this column behaves. As of 2026-09-22.

Inclusion rule. Values the aspect ratio parameter accepts on this reference page, with the default it names. The judgement column states the consequence for a placement, not a vendor claim. Order. The default first, because it is what an incomplete request gets.

1An adaptive default is the one shape a placement cannot accept

Every ad surface this register reads accepts specific shapes. A file whose shape was chosen by the model is a file whose acceptance was chosen by the model, and a batch generated without the field set can come back in several shapes across one campaign.

The fix is trivial and has to be deliberate: set the ratio on every request. It is worth a page because the failure is silent. Nothing errors, the pieces look correct on their own, and the problem appears when they are uploaded against a spec.

2Six named values sit behind the default

Once the field is set, this row publishes the same six shapes as the other explicit entry in the column, from twenty-one by nine to nine by sixteen with a square option in between. Nothing is missing; the difference between the two rows is entirely in what happens when nobody chooses.

Read together they show that a default is a specification. Two pages offering identical lists behave differently in production because one refuses to proceed and the other proceeds on its own judgement.

3Shape is unconditional here, unlike on two other rows

No tier or length condition attaches to any of the six values on this page. A vertical thirty second piece at 480P is a request the reference supports on its face, and the same is true at 1080P.

That independence is the property that makes this row the common answer for a long vertical placement. The work it leaves is administrative rather than technical: making sure the field is never left to the default in a pipeline that generates many pieces unattended.

4Where this cell sits in the column

Inclusion rule. Every generator in the register, carrying whatever its own page says about output shape. Six rows say nothing and are marked hollow rather than dropped. Order. Alphabetical by generator name.

• Aspect ratios offered
  adaptive, the default, then 21:9, 16:9, 4:3, 1:1, 3:4 and 9:16Alibaba Cloud Model Studio, Wan3.0 API reference / recorded 2026-09-22
• Resolution tiers
  1080P, 720P and 480PAlibaba Cloud Model Studio, Wan3.0 API reference / recorded 2026-09-22

5Sources

Read from the Wan3.0 API reference, checked 2026-09-22. The column itself is described on aspect ratio, and the rule that keeps surfaces and generators apart is on method. Next along this column: PixVerse, Grok Imagine.