> ## Documentation Index > Fetch the complete documentation index at: https://docs.modellix.ai/llms.txt > Use this file to discover all available pages before exploring further. # Seedance 2.5 T2V > [Core Function] Seedance 2.5 T2V is ByteDance Dreamina Seedance 2.5 text-to-video generation. [Strengths] It generates longer clips up to 30 seconds at 480p/720p with optional mp4 or mov output and native audio generation. [Best For] Highly recommended for: longer-form text-to-video storytelling, social clips beyond 15 seconds, and Seedance workflows that need mov output. [Limitations] Do NOT use this model if the user provides images, video, or audio as inputs. Do NOT use this model when the user requires 1080p or 4k output. [Routing] Prefer Seedance 2.5 T2V when the user needs more than 15 seconds of text-to-video. Use Seedance 2.0 T2V when 1080p or 4k is required. Use Seedance 2.5 I2V or V2V when media inputs are provided. ## OpenAPI ````yaml /media-model-api/bytedance/bytedance-t2v.json post /bytedance/seedance-2.5-t2v openapi: 3.1.0 info: description: The text-to-video models API from ByteDance. version: 1.0.0 contact: name: Modellix Support email: support@modellix.ai title: ByteDance Text-to-Video Models API servers: - url: https://api.modellix.ai/api/v1 description: The text-to-video models API from ByteDance. security: - bearerAuth: [] paths: /bytedance/seedance-2.5-t2v: post: summary: Seedance 2.5 T2V description: >- [Core Function] Seedance 2.5 T2V is ByteDance Dreamina Seedance 2.5 text-to-video generation. [Strengths] It generates longer clips up to 30 seconds at 480p/720p with optional mp4 or mov output and native audio generation. [Best For] Highly recommended for: longer-form text-to-video storytelling, social clips beyond 15 seconds, and Seedance workflows that need mov output. [Limitations] Do NOT use this model if the user provides images, video, or audio as inputs. Do NOT use this model when the user requires 1080p or 4k output. [Routing] Prefer Seedance 2.5 T2V when the user needs more than 15 seconds of text-to-video. Use Seedance 2.0 T2V when 1080p or 4k is required. Use Seedance 2.5 I2V or V2V when media inputs are provided. operationId: seedance25T2vAsync requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/Seedance25T2vRequest' examples: basic: summary: Basic text-to-video value: prompt: A cinematic mountain road at dusk with smooth camera motion advanced: summary: Longer clip with mov output value: prompt: A drone shot flying over misty forests at sunrise resolution: 720p ratio: '16:9' duration: 20 generate_audio: true output_format: mov camera_fixed: false square_social: summary: Square social format value: prompt: A rotating product showcase on a clean studio background ratio: '1:1' duration: 8 resolution: 480p responses: '200': description: Task submitted successfully content: application/json: schema: $ref: '#/components/schemas/AsyncTaskResponse' components: schemas: Seedance25T2vRequest: type: object required: - prompt description: >- Text-only request. Required: prompt. Images, video, and audio inputs are not supported on T2V. properties: prompt: type: string description: Text prompt describing the desired video. Maximum 10000 characters minLength: 1 maxLength: 10000 example: A cinematic mountain road at dusk with smooth camera motion ratio: type: string description: Specifies the aspect ratio for the generated video enum: - '21:9' - '16:9' - '4:3' - '1:1' - '3:4' - '9:16' default: '16:9' example: '16:9' resolution: type: string description: >- Specifies the resolution tier for the generated video. Seedance 2.5 supports 480p and 720p only enum: - 480p - 720p default: 720p example: 720p duration: type: integer description: Video duration in seconds. Allowed values are integers from 4 to 30 enum: - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - 26 - 27 - 28 - 29 - 30 default: 5 example: 5 seed: type: integer description: >- Random number seed for reproducibility. Use -1 for random. Identical seeds cannot guarantee completely identical results minimum: -1 maximum: 4294967295 default: -1 example: -1 camera_fixed: type: boolean description: Whether to keep the camera fixed during generation default: false example: false generate_audio: type: boolean description: Whether to generate an audio track with the video default: true example: true output_format: type: string description: >- Output video container. mp4 for general playback; mov for higher color precision in editing workflows enum: - mp4 - mov default: mp4 example: mp4 execution_expires_after: type: integer description: Task expiration time in seconds minimum: 3600 maximum: 259200 default: 172800 example: 172800 return_last_frame: type: boolean description: Whether to return the last frame of the generated video default: false example: false AsyncTaskResponse: type: object required: - code - message - data properties: code: type: integer description: Response code, 0 indicates success example: 0 message: type: string description: Response message example: success data: type: object required: - status - task_id - model_id properties: status: type: string enum: - pending - processing description: Task status example: pending task_id: type: string description: Unique task identifier example: task-abc123 model_id: type: string description: Model ID example: model-123 get_result: type: object description: API information to query the task result properties: method: type: string description: HTTP method example: GET url: type: string description: Full URL to query the task result example: https://api.modellix.ai/api/v1/tasks/task-abc123 description: Detailed data about the submitted asynchronous task. securitySchemes: bearerAuth: type: http scheme: bearer description: 'API Key authentication. Format: `Bearer YOUR_API_KEY`.' ````