Length, seeds and variations
4–30 seconds, up to 4 at once.
Length runs from 4 to 30 seconds, capped per model. Price is close to linear in length, because the provider bills per frame.
Variations generate up to 4 clips from the same prompt in one go, each with a different random seed. You are charged for each.
A seed makes a render repeatable: the same prompt, model, length and seed produce the same video. Set one when you want to change a single word and see only that word's effect. A fixed seed with several variations would produce identical clips, so the two cannot be combined.