The bottom bar of the storyboard editor has two controls that set how your final video is rendered: Resolution (the pixel size) and Quality (the render tier). Together they determine the per-second credit cost shown next to Generate.
What's the difference between Resolution and Quality?
Resolution is the frame size — how many pixels. The options are 720P, FHD, QHD, and 4K. FHD is the default.
Quality is the render tier — how much processing goes into each frame. The options are Ultra and Ultra S. Ultra is the default.
You pick one of each, and the pair sets the price per second.
What do Ultra and Ultra S mean?
Ultra — "Ideal for all kinds of video generation."
Ultra S — "Ideal for all kinds of video generation with enhanced quality." Both Ultra and Ultra S show a small glyph next to their label (a highlighted/light glyph on the tier that's selected, and an outline/dark glyph on the one that isn't) — so the glyph isn't unique to Ultra S.
Hovering a quality shows its description plus its cost range per second, and a "Powered by Seedance 2.0" note.
Why is 4K greyed out?
4K is only available with Ultra S. Under Ultra, the 4K button is disabled — hovering it shows "Only available for Ultra S". Switch the quality to Ultra S to unlock 4K. The other three resolutions (720P, FHD, QHD) work with either quality.
How much does it cost per second?
The bottom bar shows the per-second credit cost for your current Quality + Resolution pair (shown as "… credits/s"), and the Generate button shows the total — the per-second rate multiplied by the video's duration in seconds. Higher resolution and the Ultra S tier cost more per second. The exact numbers are shown next to Generate and depend on your plan.
How is the total video cost worked out?
It's the per-second rate for your selected Quality and Resolution, times the storyboard's total Duration (rounded to whole seconds, shown in the bottom bar). Change the quality or resolution and the per-second rate — and the total on the Generate button — update right away.
What if I pick a resolution that isn't allowed?
The controls prevent invalid combinations: if you somehow have 4K selected and switch to a quality that doesn't support it, the app normalizes the resolution to a supported one before rendering, so you never send an unsupported pair.
On mobile
Resolution and Quality sit in the bottom bar in a compact form — Resolution and Quality as small dropdowns, followed by the per-second Cost and the total Duration, with the Generate button below. Tapping a disabled 4K option shows the same "Only available for Ultra S" message as a toast.