Seedance 2.5 Draft Final

Seedance 2.5 Draft Final — Draft-to-1080p Video Renderer

What is Seedance 2.5 Draft Final?

Seedance 2.5 Draft Final is the finishing half of ByteDance's two-step Seedance 2.5 video workflow. You first render a fast, low-cost 480p draft with seedance-2.5 using draft: true, which returns a draft_task_id. You send that id here and the model renders the exact same shot at full 1080p, keeping the draft's composition, subject, structure and motion, together with the native audio generated in the same pass. Because the prompt, references, duration, aspect ratio, seed and audio are all inherited from the draft, the final is deterministic against it: you preview cheaply, then spend the 1080p budget only on the take you approve.

Key Features

• •Draft-to-final 1080p rendering from a draft_task_id, valid for 7 days after the draft.
• •Native synchronized audio inherited from the draft, so dialogue, sound effects and ambience land already in sync.
• •return_last_frame emits the final frame as an image URL for seamless shot chaining.
• •output_codec chooses the 10-bit HEVC master (auto) or a browser-safe H.264 re-encode (h264).
• •output_format mp4 for compatibility or mov for color-accurate edit round-trips.
• •Inherits duration up to 30 seconds and every aspect ratio from the draft, including 16:9 and vertical 9:16.

Best Use Cases

The core use case is cost-controlled finishing for production video. Teams storyboard and iterate at 480p, then finalize only approved takes at delivery quality, getting the identical shot back at 1080p. In testing, a wok flambé toss finalized with fast, physically legible motion and synchronized sizzle audio; a glassblowing clip finalized in 16:9 and returned a last frame for chaining; and a wind-up toy finalized as a true vertical 1080x1920 clip for Reels and Shorts. That fits ad spots, product demos, social cutdowns and multi-shot sequences where one beat must ship clean.

Prompt Tips and Output Quality

Prompts live in the draft, not here. Write the draft with concrete nouns, one clear action and audio cues, then finalize. Set output_codec to h264 for browser playback and previews; leave it on auto only when the file goes into a grade. Use return_last_frame to build longer sequences.

How to Use Seedance 2.5 Draft Final

Seedance 2.5 Draft Final finishes a Seedance 2.5 draft at full 1080p. The flow is two steps. First, render a draft with seedance-2.5 using draft: true at 480p and keep the draft_task_id it returns (header X-Draft-Task-ID, or video.draft_task_id on /v2). Then send that id here within 7 days. Everything creative — prompt, references, duration, aspect ratio, seed and audio — is inherited from the draft and cannot be changed at this stage, so get the shot right in the draft before you finalize.

Recommended Settings

• •draft_task_id: the id from your approved 480p draft. This is the only required input.
• •output_codec: set h264 for browser embeds, previews and social; keep auto (10-bit HEVC) only when the clip goes into an editor or color grade.
• •output_format: mp4 for broad compatibility; mov for higher color fidelity in edit and extension round-trips.
• •return_last_frame: enable when you plan to chain shots into a longer sequence.
• •Cost control: iterate at 480p, keep drafts short, and finalize only the take you approve — 4s 16:9 is the cheapest 1080p finalize tier.

Example renders to try

Each example below was rendered end to end at the settings shown; the 1080p final reproduced the draft's framing, motion and audio one-to-one.

• •Draft-to-1080p with native audio (default). Prompt: "A street cook's hands toss jasmine rice, pink prawns and sliced spring onion high out of a blackened carbon-steel wok over a roaring blue gas flame..." The final matched the draft's toss exactly with a synced sizzle track. Tip: keep the draft at 4s and 16:9 for the cheapest full-quality finalize.
• •Chain shots with return_last_frame. Prompt: "A glassblower rotates a glowing orange gob of molten glass on a steel blowpipe at the mouth of a roaring furnace..." With return_last_frame: true the response added video.last_frame_url. Tip: feed that image into the next generation's first_frame_url to extend without a seam.
• •Vertical 9:16 for social. Prompt: "A wind-up tin robot marches across a scuffed wooden desk, its brass key turning and painted chest gears spinning..." Because aspect ratio is inherited, drafting in 9:16 returned a true 1080x1920 final. Tip: draft vertical up front — you cannot switch aspect ratio at the finalize stage.

Further shots the model is built for: "finalize a 30-second single-pass draft at 1080p", "finalize a reference-driven multi-subject scene", and "chain three finalized clips into one sequence".

Where does draft_task_id come from?

A seedance-2.5 render with draft: true (response header X-Draft-Task-ID, or video.draft_task_id on /v2).

How long is the draft_task_id valid?

Seven days from the draft render.

Can I change the prompt or duration when finalizing?

No. Prompt, duration, aspect ratio, seed and audio are inherited from the draft.

My video plays black with sound. Why?

The auto codec is 10-bit HEVC that some Windows browsers cannot decode; set output_codec to h264.

What resolution does it output?

1080p, 24fps, with 10-bit color on the auto master.