Bytedance Seedance 2.0 Video Extend
Playground
Try it on WavespeedAI!Seedance 2.0 (Video-Extend) extends an input video with a new cinematic continuation generated from its last frame and a natural-language prompt.
Features
Seedance 2.0 Video-Extend
Seedance 2.0 Video-Extend appends a new cinematic continuation to an existing video. The model generates a fresh segment from the input video’s last frame and a natural-language prompt, then the original and new segment are concatenated into a single output.
Key Features
- Seamless continuation — Generation starts from the input video’s last frame so the join is visually consistent.
- Optional target last frame — Provide
last_imageto steer the new segment toward a specific end frame. - Director-level control — Camera movement, lighting, shadows, and character performance via prompts.
- Native audio synchronization — Audio from both the original video and the new segment are preserved in the final output.
Parameters
| Parameter | Required | Description |
|---|---|---|
| prompt | Yes | Describe the cinematic continuation. |
| video | Yes | Input video URL. Generation continues from the last frame. |
| last_image | No | Optional target last-frame URL. Interpolates from the input’s last frame to this image. |
| duration | No | Length in seconds of the new segment (4-15, default 5). |
| resolution | No | 480p, 720p (default), or 1080p. |
| enable_web_search | No | Enable web search for real-time context. |
How to Use
- Upload the input video. The new segment will be appended to it.
- Write the prompt. Describe the continuation in cinematic detail.
- (Optional) Upload a target last frame. The new segment will interpolate to this image.
- Pick a duration and resolution.
- Run. Receive the original video plus the new segment concatenated into one output.
Pricing
Billed per second of the new segment only. Resolution multipliers match Seedance 2.0 image-to-video.
| Resolution | Per second |
|---|---|
| 480p | $0.12 |
| 720p | $0.24 |
| 1080p | $0.60 |
Examples (5s extension):
| Resolution | Cost |
|---|---|
| 480p | $0.60 |
| 720p | $1.20 |
| 1080p | $3.00 |
Notes
- Pricing is based on the new segment length only — the input video is not re-billed.
- Aspect ratio of the new segment matches the input video’s last frame automatically.
- Native audio generation is included for the new segment; the original video’s audio is preserved.
Related Models
- Seedance 2.0 Image-to-Video — Generate video from a reference image and prompt.
- Seedance 2.0 Video-Edit — Edit an existing video instead of extending it.
- Seedance 2.0 Fast Video-Extend — Faster, cheaper variant.
Authentication
For authentication details, please refer to the Authentication Guide.
API Endpoints
Submit Task & Query Result
# Submit the task
curl --location --request POST "https://api.wavespeed.ai/api/v3/bytedance/seedance-2.0/video-extend" \
--header "Content-Type: application/json" \
--header "Authorization: Bearer ${WAVESPEED_API_KEY}" \
--data-raw '{
"resolution": "720p",
"duration": 5,
"enable_web_search": false
}'
# Get the result
curl --location --request GET "https://api.wavespeed.ai/api/v3/predictions/${requestId}/result" \
--header "Authorization: Bearer ${WAVESPEED_API_KEY}"
Parameters
Task Submission Parameters
Request Parameters
| Parameter | Type | Required | Default | Range | Description |
|---|---|---|---|---|---|
| prompt | string | Yes | - | Describe the cinematic continuation — action, camera movement, lighting, mood. | |
| video | string | Yes | - | URL of the input video to extend. Generation continues from the last frame. | |
| last_image | string | No | - | - | Optional target last-frame URL. If provided, the new segment interpolates from the input video's last frame to this image. |
| resolution | string | No | 720p | 480p, 720p, 1080p | Output resolution of the new segment. |
| duration | integer | No | 5 | 4 ~ 15 | Length in seconds of the new segment to append (4-15). |
| enable_web_search | boolean | No | false | - | Enable web search for real-time information. |
Response Parameters
| Parameter | Type | Description |
|---|---|---|
| code | integer | HTTP status code (e.g., 200 for success) |
| message | string | Status message (e.g., “success”) |
| data.id | string | Unique identifier for the prediction, Task Id |
| data.model | string | Model ID used for the prediction |
| data.outputs | array | Array of URLs to the generated content (empty when status is not completed) |
| data.urls | object | Object containing related API endpoints |
| data.urls.get | string | URL to retrieve the prediction result |
| data.has_nsfw_contents | array | Array of boolean values indicating NSFW detection for each output |
| data.status | string | Status of the task: created, processing, completed, or failed |
| data.created_at | string | ISO timestamp of when the request was created (e.g., “2023-04-01T12:34:56.789Z”) |
| data.error | string | Error message (empty if no error occurred) |
| data.timings | object | Object containing timing details |
| data.timings.inference | integer | Inference time in milliseconds |
Result Request Parameters
| Parameter | Type | Required | Default | Description |
|---|---|---|---|---|
| id | string | Yes | - | Task ID |
Result Response Parameters
| Parameter | Type | Description |
|---|---|---|
| code | integer | HTTP status code (e.g., 200 for success) |
| message | string | Status message (e.g., “success”) |
| data | object | The prediction data object containing all details |
| data.id | string | Unique identifier for the prediction, the ID of the prediction to get |
| data.model | string | Model ID used for the prediction |
| data.outputs | object | Array of URLs to the generated content (empty when status is not completed). |
| data.urls | object | Object containing related API endpoints |
| data.urls.get | string | URL to retrieve the prediction result |
| data.status | string | Status of the task: created, processing, completed, or failed |
| data.created_at | string | ISO timestamp of when the request was created (e.g., “2023-04-01T12:34:56.789Z”) |
| data.error | string | Error message (empty if no error occurred) |
| data.timings | object | Object containing timing details |
| data.timings.inference | integer | Inference time in milliseconds |