Wan 2.6 to Wan 3.0 Migration: Every Field That Changes

Siray.AI

• 3 min read
Wan 2.6 to Wan 3.0 Migration: Every Field That Changes
Wan 2.6 to Wan 3.0 Migration: Every Field That Changes

Teams treating this as a find-and-replace on the model ID are the ones filing support tickets. Both generations answer the same route, but the body they accept is not.

Key Takeaways

  • size changes type, not just values: Wan 2.6 takes pixel strings, Wan 3.0 takes tier names 480p, 720p, 1080p.
  • aspect_ratio is required on every Wan 3.0 call and does not exist in Wan 2.6.
  • prompt_expansion_enable defaults to true, so ported prompts get rewritten unless you turn it off.
Wan 3.0 Image: hipertextual
Wan 3.0 Image: hipertextual

What the Request Body Looks Like on Both Sides

Field
Wan 2.6 t2v
Wan 3.0 t2v
model
Required, one of three strings
Required, one string
prompt
Required
Required
duration
Required, 5 / 10 / 15
Required, any integer 2–30
size
Required, ten pixel strings
Required, 480p / 720p / 1080p
aspect_ratio
Not present
Required, six values
seed
Not present
Optional
audio_enable
Not present
Optional
prompt_expansion_enable
Not present
Optional, default true
negative_prompt
Not present
Not present

size Is the Breaking Change

Wan 2.6 encodes resolution and shape in one value. Its ten strings range from 1280x720 up to 1920x1080, including 960x960, 1440x1440, 1632x1248 and their vertical twins. Ask for 1080x1920 and you have ordered vertical and 1080p at once.

Wan 3.0 splits that in two. size carries resolution, aspect_ratio carries shape, and since shape has nowhere else to live the field is required. Vertical did not arrive with 3.0, it moved: 1080x1920 becomes size: "1080p" plus aspect_ratio: "9:16". Exact pixel dimensions do not survive, so a pipeline pinned to 1632x1248 has no literal equivalent.

What You Get for the Trouble

  • seed, from -1 to 2147483647. Wan 2.6 has none, so a shot you liked was gone once you closed the tab.
  • end_image on i2v, so you can pin the last frame as well as the first.
  • One-second granularity from 2 to 30 seconds instead of three fixed lengths.
  • A ref2v endpoint with no 2.6 counterpart, taking up to 10 images, 5 videos and 5 audio files.
  • audio_enable, listed with no declared default. Set it explicitly.

What does not arrive: negative_prompt is absent from both generations, so prompts leaning on phrasing tricks to suppress artifacts still have to.

Wan Video Generator image: Kenerate ai
Wan Video Generator image: Kenerate ai

What the Swap Costs

Wan 2.6 t2v is not one rate. Its ten sizes fall into two bands on the console pricing table: the five 720p-class sizes list at $0.10/s and the five 1080p-class sizes at $0.15/s, both carrying a 20% off badge today, so $0.08/s and $0.12/s. Wan 3.0 is on a Launch Week 25% off: 480p $0.060 to $0.045/s, 720p $0.120 to $0.090/s, 1080p $0.240 to $0.180/s.

Match the resolution and Wan 3.0 costs more, roughly 12% at 720p and 50% at 1080p. The saving sits at the bottom of the range. Wan 2.6 has no tier below 720p-class and no duration under 5 seconds, so its cheapest run is $0.40, while Wan 3.0 will do a 2-second 480p test for $0.09. Both discounts are promotional, so check the current Launch Week rates before budgeting.

The Migration Checklist

  1. Swap the model string and delete any resolution-based routing: Wan 2.6 spread resolution across -t2v-720p and -t2v-1080p, Wan 3.0 keeps one string per task.
  2. Convert size from pixels to a tier, then pass the shape as aspect_ratio.
  3. Add both fields to image-to-video calls. Wan 2.6 i2v had no size either.
  4. Set prompt_expansion_enable deliberately, or the service rewrites prompts you already tuned.
  5. Set audio_enable explicitly, since the spec declares no default.
  6. Re-time jobs. Durations are no longer locked to 5, 10 and 15 seconds.
  7. Re-price. The two-band table is gone and a cheaper 480p tier exists.

FAQ

Does Wan 3.0 add negative prompts?

No. Neither generation exposes a negative_prompt field on any endpoint, so prompt phrasing stays the only lever.

Can I keep exact pixel dimensions like 1632x1248?

No. Wan 3.0 accepts only 480p, 720p and 1080p for size, with shape passed separately as aspect_ratio. Pick the nearest tier and ratio.

Is Wan 3.0 cheaper than Wan 2.6?

Not at the same resolution. It is cheaper per run only if you drop to the new 480p tier or go shorter than 5 seconds.

Run Both While You Migrate

Both generations are live on Siray behind one API key, so Wan 2.6 can keep serving traffic while Wan 3.0 takes a copy and you compare output before cutting over. Create your free Siray account and run the two side by side.