Quality and upscale — what to pick
Two separate choices. The default is the best value, and it is not a compromise.
Quality is what the model renders. Upscale is what happens to that render afterwards. They are separate because they cost very differently: the render dominates the bill, so buying resolution at the upscaler is far cheaper than rendering it.
For a 5 and 10 second clip on Seedance 2.5:
| Route | Rendered at | Delivered | 5s | 10s |
|---|---|---|---|---|
| 480p → 4K | 480p | 3840x2160 | $0.77 | $1.53 |
| 480p → 1080p | 480p | 1920x1080 | $0.65 | $1.28 |
| 480p as rendered | 480p | 480p | $0.61 | $1.20 |
| 720p → 4K | 720p | 3840x2160 | $1.52 | $3.00 |
| 720p → 1080p | 720p | 1920x1080 | $1.39 | $2.76 |
| 720p as rendered | 720p | 720p | $1.35 | $2.68 |
| 1080p → 4K | 1080p | 3840x2160 | $2.55 | $5.05 |
| 1080p as rendered | 1080p | 1080p | $2.38 | $4.73 |
That is why the default is 480p → 4K: it delivers 3840×2160 for less than a native 1080p render costs, because the expensive part — the model — is doing less work.
When native 1080p is worth it: the upscaler infers detail that was not in the 480p render, and on fine texture, small faces and dense foliage that inference can look synthetic. A native render has no interpolated detail. You are paying several times more for that honesty.