Seedance 2.5 shortest clip: what 4 seconds costs vs Seedance 2, Wan 3

The shortest Seedance 2.5 clip on Sume is 4 seconds, and it costs $1.074708 at 480p, $2.3112 at 720p and $5.6862 at 1080p (4 s x the per-second price). Seedance 2 has the same 4-second floor but costs roughly 35 to 40 percent less at the same resolution, and Wan 3.0 can go down to 2 seconds at a fraction of the price.

The floor on each model

Seedance 2.5 accepts 4-30 seconds, so 4 seconds is the minimum billed length. Seedance 2 accepts 4-15 seconds. Wan 3.0 accepts 2-30 seconds. These ranges are the valid duration limits in the Sume model catalog; a shorter request than the model's minimum is outside its range, so plan around 4 seconds when you pick Seedance.

The table shows the full price of a 4-second clip, with the per-second rate in brackets so you can scale it. All three scale linearly inside their ranges.

Seedance 2.5 against Seedance 2

At every resolution the ratio between Seedance 2 and 2.5 is the same. 720p: $0.378 / $0.5778 = 0.654. 1080p: $0.8505 / $1.42155 = 0.598. 480p: $0.17577 / $0.268677 = 0.654. Seedance 2 is roughly 35-40 percent cheaper per second.

For a 4-second 720p shot, Seedance 2 is $1.512 and Seedance 2.5 is $2.3112, a $0.7992 difference per clip. Across 250 test clips that is 250 x $0.7992 = $199.80, which is the real cost of choosing the newer model for pure iteration.

When 2 seconds is enough

Wan 3.0 is the only one of the three that goes below 4 seconds. A 2-second Wan 3.0 clip is $0.125 at 480p, $0.25 at 720p and $0.50 at 1080p. If you need a reaction cut or a bumper rather than a full shot, that is roughly a ninth of the cost of the shortest Seedance 2.5 clip at the same resolution.

The practical rule: use the shortest valid clip for tests, and extend to your real length only after the prompt works. Test at 4 seconds, then run the production length.

• Seedance 2.5: 4-30 s
• Seedance 2: 4-15 s
• Wan 3.0: 2-30 s

A second scenario

Price a three-model test at 720p. One 4-second clip each: Seedance 2.5 $2.3112, Seedance 2 $1.512 and Wan 3.0 $0.50. The three together cost $4.3232, about $4.32. That is the cheapest way to see which model suits your prompt before any batch run, and it is far less than a single 1080p Seedance 2.5 clip of 4 seconds plus its retakes.

Where to check

Prices come from the public catalog at api.sume.com/v1/catalog, and the duration limits are on the Video generation and Video Router docs pages. Both are linked in the sources below. If either changes, recompute with the same formula: seconds x per-second price.

Reproduce the numbers

Open https://api.sume.com/v1/catalog, which needs no key, and find the entry for the product. Each model_pricing row carries price, unit, pricing_basis and the estimated, minimum and maximum cents. Multiply the unit price by your quantity and round only at the end. The catalog also has applied_* fields that include an agent fee of 550 basis points; the figures in this post use the base prices.