The Seedance family, from 1.0 to 2.5
Seedance 2.5 makes the longest video and takes the most reference input, but it stops at 720p where Seedance 2.0 went to 4K. So which version to use depends on whether length or sharpness matters more to you.
- five versions since April 2025
- 2.0 to 4K, 2.5 to 720p
- release date inside the model id
Last checked: This is a reference page. It is re-checked against the vendor sources and updated when a new version ships. What changed
Which version to use
If you want length and reference control, 2.5. It makes thirty seconds in a single generation, can be extended twice, and takes more reference input than any other version in this family.
If you want resolution, 2.0. That sentence is strange and it is correct: on the Runway price list the older version has four resolution rows going up to 4K, and the newer one has only two, 480p and 720p. If your output has to go on a large screen, upgrading to 2.5 is a step backwards.
The timeline, read off the model ids
ByteDance puts the release date inside the model id, so this timeline is not a guess. doubao-seedance-1-0-lite-i2v-250428 on 28 April 2025, doubao-seedance-1-0-pro-250528 on 28 May, doubao-seedance-1-5-pro-251215 on 15 December, doubao-seedance-2-0-260128 on 28 January 2026 and doubao-seedance-2-5-260628 on 28 June 2026.
One more thing shows up in that same list: 1.0 and 1.5 carried tier suffixes, pro and lite, and from 2.0 onward the suffix is gone entirely. The family went from two tiers to a single model, and tiering moved out to the resellers; Runway today has its own fast and mini variants that appear nowhere in ByteDance list.
The number that proves the regression
On the Runway price list, Seedance 2.0 is thirty six credits a second at 480p and 720p, forty at 1080p and a hundred and fifty at 4K. Seedance 2.5 has two rows: 720p at thirty credits and 480p at twenty. A price table is not a marketing page; if 2.5 produced 4K output, there would be a row for it.
ByteDance has not written this down anywhere. Its own 2.5 page never states a resolution figure across its whole text, and the Seedance 1.0 page on the same site still headlines "1080p videos". That is why on this page the resolution figure is attributed to Runway and not to the maker.
A pattern we have now seen twice
Seedance is the second family here whose newest member is not the right default. The first was Grok 4, where 4.5 has half the context window of 4.3 and costs more. In both cases the vendor presents the new version as a replacement and its own specification table says it is not.
Release timeline
Each version with its own release date, and what changed against the one before it.
- Seedance 2.5 current The length ceiling went from 15 to 30 seconds and the reference ceiling from 12 to 50, but the 4K that Seedance 2.0 had is not in 2.5.
Where it falls short
- The 2.5 resolution ceiling does not go above 720p, and against 2.0 that is a regression.
- ByteDance publishes no resolution for either 2.x version, so this figure comes from a reseller price list.
- We have not read the official yuan price on the Volcano Engine console, so the only price on this page is Runway.
- No version in this family publishes a speech language list, so we know nothing about Persian.
Our take
Make 2.5 the default, because its length and reference control genuinely are ahead. But before you migrate, ask once where the output is going to be played; if the answer is a large screen, 2.0 is still the only member of this family that gives you 4K.