Seedance API Parameters: Duration, Resolution, Ratio and References

Review Seedance API parameter types, defaults, valid ranges, supported models, local validation and upstream field mappings.

Provider: Volcano Engine China · Last verified: 2026-07-13

Parameter contract

Unknown fields are rejected. Locally validated fields use the selected model registry for type, enum, range, URL, and combination checks. The callback URL is explicitly type-checked and passed through without a model-specific interpretation.

Field	Type	Required	Default	Values / range	Models	Validation	Upstream field
`model`	string	No	`seedance-2-0`	string	All registered models	Local	`model`
`content`	array	One input source	`—`	Validated text, image, video, audio, frame, or draft items supported by the model	All registered models	Local	`content`
`prompt`	string	One input source	`—`	string	All registered models	Local	`content[].text`
`draft_task_id`	string	One input source	`—`	string	Seedance 1.5 Pro	Local	`content[].draft_task.id`
`resolution`	enum	No	`720p / 1080p`	480p, 720p, 1080p	All registered models	Local	`resolution`
`ratio`	enum	No	`adaptive / 16:9`	adaptive, 16:9, 4:3, 1:1, 3:4, 9:16, 21:9	All registered models	Local	`ratio`
`duration`	integer	No	`5`	4–15, -1, 4–12, 2–12	All registered models	Local	`duration`
`frames`	integer	No	`—`	29–289	Seedance 1.0 Pro, Seedance 1.0 Pro Fast	Local	`frames`
`first_frame_url`	URL	One input source	`—`	HTTP(S) URL	All registered models	Local	`content[] first_frame`
`last_frame_url`	URL	No	`—`	HTTP(S) URL	Seedance 2.0, Seedance 2.0 Fast, Seedance 2.0 Mini, Seedance 1.5 Pro, Seedance 1.0 Pro	Local	`content[] last_frame`
`image_url`	URL array	One input source	`—`	maximum 9 HTTP(S) URLs	Seedance 2.0, Seedance 2.0 Fast, Seedance 2.0 Mini	Local	`content[] reference_image`
`video_url`	URL array	One input source	`—`	maximum 3 HTTP(S) URLs	Seedance 2.0, Seedance 2.0 Fast	Local	`content[] reference_video`
`audio_url`	URL array	No	`—`	maximum 3 HTTP(S) URLs	Seedance 2.0, Seedance 2.0 Fast, Seedance 2.0 Mini	Local	`content[] reference_audio`
`generate_audio`	boolean	No	`true`	true, false	Seedance 2.0, Seedance 2.0 Fast, Seedance 2.0 Mini, Seedance 1.5 Pro	Local	`generate_audio`
`return_last_frame`	boolean	No	`false`	true, false	All registered models	Local	`return_last_frame`
`service_tier`	enum	No	`default`	default, flex	Seedance 1.5 Pro, Seedance 1.0 Pro, Seedance 1.0 Pro Fast	Local	`service_tier`
`draft`	boolean	No	`false`	true, false	Seedance 1.5 Pro	Local	`draft`
`seed`	integer	No	`—`	-1–4294967295	Seedance 1.5 Pro, Seedance 1.0 Pro, Seedance 1.0 Pro Fast	Local	`seed`
`camera_fixed`	boolean	No	`false`	true, false	Seedance 1.5 Pro, Seedance 1.0 Pro, Seedance 1.0 Pro Fast	Local	`camera_fixed`
`watermark`	boolean	No	`false`	true, false	All registered models	Local	`watermark`
`web_search`	boolean	No	`false`	true, false	Seedance 2.0, Seedance 2.0 Fast, Seedance 2.0 Mini	Local	`tools: web_search`
`priority`	integer	No	`—`	0–9	Seedance 2.0, Seedance 2.0 Fast, Seedance 2.0 Mini	Local	`priority`
`execution_expires_after`	integer	No	`—`	3600–259200	All registered models	Local	`execution_expires_after`
`safety_identifier`	string	No	`—`	string	All registered models	Local	`safety_identifier`
`callback_url`	URL	No	`—`	HTTPS URL	All registered models	Typed passthrough	`callback_url`

Native content[]

Native items are validated for object shape, type, nested URL/text data, role, model support, and reference limits. Do not mix native content with convenience content fields in the same request.

json

{
  "model": "seedance-2-0",
  "content": [
    { "type": "text", "text": "A runner crossing a misty bridge" },
    {
      "type": "video_url",
      "video_url": { "url": "https://example.com/motion-reference.mp4" },
      "role": "reference_video"
    }
  ],
  "duration": 6,
  "resolution": "720p"
}

Convenience fields

Convenience fields are converted to provider content[]parts after validation. A single URL string for image_url,video_url, or audio_url is normalized to a one-item array for backward compatibility.

bash

curl https://api.seedanceapi.app/v1/videos/generations \
  -H "Authorization: Bearer sk_live_xxx" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "seedance-2-0",
    "prompt": "A continuous cinematic camera move",
    "first_frame_url": "https://example.com/first-frame.png",
    "duration": 5,
    "ratio": "16:9",
    "resolution": "720p"
  }'

Combination rules

last_frame_url requires first_frame_url.
Frame inputs cannot be mixed with multimodal references.
Reference audio requires at least one image or video reference.
A draft task cannot be mixed with prompt or media input.
At least one prompt, frame, reference, native content item, or draft task is required.

Seedance 2.0 constraints

Full 2.0: 480p, 720p, 1080p.
Fast and Mini: 480p or 720p.
Duration: integer 4–15 or -1.
frames is rejected; use duration.
fps is rejected because no verified mapping is configured.

return_last_frame

See the dedicated return_last_frame guidefor result shape and continuous-video workflows.