Seedance 2.0 Ultra

Seedance 2.0 Ultra is ByteDance’s latest video generation model, available through the Starrise AI API. It supports text-to-video, image-to-video, multimodal reference input, video editing, video extension, and synchronized audio generation.

Key Capabilities

Feature	Description
Text-to-video	Generate video from a text description
Image-to-video (first frame)	Use one image as the first frame
Image-to-video (first and last frame)	Use two images as the first and last frames respectively
Multimodal reference	Combine images, video, and audio as references (1–9 images, up to 3 videos, up to 3 audio clips)
Video editing	Modify elements in an existing video using a reference image
Video extension	Extend and concatenate reference videos
Audio generation	Automatically generate synchronized voice, sound effects, and background music
Web search enhancement	Enhance generation with real-time internet content (text-to-video only)
Return last frame	Retrieve the last frame of the generated video

Output Specifications

Property	Value
Resolution	720p, 1080p, 2k
Aspect ratio	16:9, 4:3, 1:1, 3:4, 9:16, 21:9, adaptive
Duration	4–15 seconds
Format	mp4

Workflow

POST /v1/video/generations  →  task_id
Poll GET /v1/video/generations/{task_id}  →  status
When status = "succeeded"  →  download video URL (valid for 24 hours)

Examples

Text-to-Video

curl https://ai.alad.com/v1/video/generations \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "seedance-2.0-ultra",
    "content": [
      {
        "type": "text",
        "text": "A cat playing piano in a sunlit room, cinematic lighting"
      }
    ],
    "generate_audio": true,
    "ratio": "16:9",
    "duration": 8
  }'

import requests
import time

headers = {"Authorization": "Bearer YOUR_API_KEY", "Content-Type": "application/json"}

# Step 1: Create task
resp = requests.post(
    "https://ai.alad.com/v1/video/generations",
    headers=headers,
    json={
        "model": "seedance-2.0-ultra",
        "content": [
            {"type": "text", "text": "A cat playing piano in a sunlit room, cinematic lighting"}
        ],
        "generate_audio": True,
        "ratio": "16:9",
        "duration": 8
    }
)
task_id = resp.json()["task_id"]

# Step 2: Poll for results
while True:
    result = requests.get(
        f"https://ai.alad.com/v1/video/generations/{task_id}",
        headers=headers
    ).json()
    status = result["data"]["status"]
    if status == "SUCCESS":
        print("Video URL:", result["data"]["data"]["content"]["video_url"])
        break
    elif status == "FAILED":
        print("Failed:", result["data"].get("fail_reason"))
        break
    time.sleep(5)

Multimodal Reference (Image + Video + Audio)

In the prompt you can reference content array items using @image1, @video1, @audio1, numbered by media type starting from 1.

Important: Assets must be passed in strict order: text, image_url, video_url, audio_url. Do not reorder them, as this may cause errors; when including multiple assets, also ensure no other asset types are mixed in.

cURL

curl https://ai.alad.com/v1/video/generations \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "seedance-2.0-ultra",
    "content": [
      {
        "type": "text",
        "text": "The character from @image1 dances in the scene from @video1, with @audio1 as background music, festive New Year atmosphere"
      },
      {
        "type": "image_url",
        "image_url": {"url": "https://example.com/character.jpg"},
        "role": "reference_image"
      },
      {
        "type": "video_url",
        "video_url": {"url": "https://example.com/clip.mp4"},
        "role": "reference_video"
      },
      {
        "type": "audio_url",
        "audio_url": {"url": "https://example.com/bgm.mp3"},
        "role": "reference_audio"
      }
    ],
    "generate_audio": true,
    "ratio": "16:9",
    "duration": 11
  }'

Video Editing

cURL

curl https://ai.alad.com/v1/video/generations \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "seedance-2.0-ultra",
    "content": [
      {
        "type": "text",
        "text": "Replace the water in @video1 with the perfume from @image1, keep the same camera motion"
      },
      {
        "type": "image_url",
        "image_url": {"url": "https://example.com/perfume.jpg"},
        "role": "reference_image"
      },
      {
        "type": "video_url",
        "video_url": {"url": "https://example.com/original.mp4"},
        "role": "reference_video"
      }
    ],
    "generate_audio": true,
    "ratio": "16:9",
    "duration": 5
  }'

Web Search Enhancement (Text-to-Video Only)

cURL

curl https://ai.alad.com/v1/video/generations \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "seedance-2.0-ultra",
    "content": [
      {
        "type": "text",
        "text": "Macro shot of vivid flower petals on a tree, gradually zooming in"
      }
    ],
    "generate_audio": true,
    "ratio": "16:9",
    "duration": 11,
    "tools": [{"type": "web_search"}]
  }'

Request Parameters

Parameter	Type	Required	Description
`model`	string	Yes	`seedance-2.0-ultra`
`content`	array	Yes	Input content array (text, image_url, video_url, audio_url)
`content[].type`	string	Yes	`text`, `image_url`, `video_url`, or `audio_url`
`content[].text`	string	For text type	Text prompt (recommended ≤500 Chinese chars or ≤1000 English words)
`content[].image_url.url`	string	For image type	Image URL, Base64, or `asset://<ID>`
`content[].video_url.url`	string	For video type	Video URL or `asset://<ID>` (mp4/mov, ≤50 MB, 2–15 seconds)
`content[].audio_url.url`	string	For audio type	Audio URL, Base64, or `asset://<ID>` (wav/mp3, ≤15 MB)
`content[].role`	string	Conditionally	`first_frame`, `last_frame`, `reference_image`, `reference_video`, `reference_audio`
`generate_audio`	boolean	No	Generate synchronized audio, default `true`
`resolution`	string	Yes	`720p`, `1080p`, or `2k`. Required for Ultra.
`ratio`	string	No	`16:9`, `4:3`, `1:1`, `3:4`, `9:16`, `21:9`, `adaptive`, default `adaptive`
`duration`	integer	No	4–15 seconds, default `5`
`tools`	array	No	`[{"type": "web_search"}]` enables web search (text-to-video only)
`watermark`	boolean	No	Whether to add a watermark, default `false`

Input Modes

Mode	Content items	`role` values
Text-to-video	1× text	—
Image-to-video (first frame)	text (optional) + 1× image_url	`first_frame` or omitted
Image-to-video (first and last frame)	text (optional) + 2× image_url	`first_frame` + `last_frame`
Multimodal reference	text (optional) + images/videos/audio	`reference_image`, `reference_video`, `reference_audio`
Video editing	text + image_url + video_url	`reference_image` + `reference_video`
Video extension	text + video_url(s)	`reference_video`

Note: First frame, first-and-last-frame, and multimodal reference are three mutually exclusive modes that cannot be combined.

Referencing Assets in Prompts

In the text prompt you can use @<type><N> placeholders to reference media items in the content array, numbered in order of appearance within each media type:

Placeholder	Referenced item
`@image1`, `@image2`, …	1st, 2nd, … `image_url` item
`@video1`, `@video2`, …	1st, 2nd, … `video_url` item
`@audio1`, `@audio2`, …	1st, 2nd, … `audio_url` item

Example: "The character from @image1 walks through the scene in @video1, with @audio1 as background music".

Note: Assets must be passed in strict order: text, image_url, video_url, audio_url. Do not reorder them, as this may cause errors; when including multiple assets, also ensure no other asset types are mixed in.

Resolution and Pixel Values by Aspect Ratio

Resolution	16:9	4:3	1:1	3:4	9:16	21:9
720p	1280x720	1112x834	960x960	834x1112	720x1280	1470x630
1080p	1920x1080	1664x1248	1440x1440	1248x1664	1080x1920	2208x944
2k	2560x1440	2224x1668	1920x1920	1668x2224	1440x2560	2944x1260

API Reference

View the interactive API documentation for Seedance 2.0 Ultra.

Quick Start

Models

Resources

Key Capabilities

Output Specifications

Workflow

Examples

Text-to-Video

Multimodal Reference (Image + Video + Audio)

Video Editing

Web Search Enhancement (Text-to-Video Only)

Request Parameters

Input Modes

Referencing Assets in Prompts

Resolution and Pixel Values by Aspect Ratio

API Reference

​Key Capabilities

​Output Specifications

​Workflow

​Examples

​Text-to-Video

​Multimodal Reference (Image + Video + Audio)

​Video Editing

​Web Search Enhancement (Text-to-Video Only)

​Request Parameters

​Input Modes

​Referencing Assets in Prompts

​Resolution and Pixel Values by Aspect Ratio

API Reference

Key Capabilities

Output Specifications

Workflow

Examples

Text-to-Video

Multimodal Reference (Image + Video + Audio)

Video Editing

Web Search Enhancement (Text-to-Video Only)

Request Parameters

Input Modes

Referencing Assets in Prompts

Resolution and Pixel Values by Aspect Ratio