Seedance aspect ratios, resolutions and durations.

The Seedance 2.0 line generates clips of 4 to 15 seconds, at 480p or 720p, in six fixed aspect ratios plus adaptive. The console lists the exact limits for each model, including seedance-2.5.

Aspect ratios and where they're used

If a campaign needs several placements, generate each ratio from the same prompt instead of cropping one master. Cropping a 16:9 clip to 9:16 throws away most of the frame and the resolution with it, and the subject may leave the crop as the camera moves.

Composing for each ratio

• Vertical (9:16, 3:4). Put one subject in the center third and keep faces and products away from the top and bottom edges, where placements often overlay buttons and captions. Tilts and crane moves suit the tall frame.
• Square (1:1). Center the subject and keep the action compact. Orbits and push-ins work well; wide pans have little room.
• Landscape (16:9, 4:3). Use the width: tracking shots, pans and subjects placed off-center with space to move into.
• Ultra-wide (21:9). Landscapes, skylines and slow moves. Keep the key action in the middle half if the banner may be cropped on smaller screens.
• Adaptive. Use it only with a first frame. Check the source image's shape before you submit, because the output follows it.

Write composition into the prompt ("subject centered, space above for a caption") and put the ratio itself in the request.

480p or 720p

480p is enough to judge composition, motion and timing, so most iterations can stay there. Render at 720p once the prompt is settled. If a placement asks for a larger file than the model outputs, upscale in your editing tool and check the result on the target screen before you publish.

Choosing a duration

Duration is a whole number of seconds from 4 to 15. Choose the length the action needs, not the longest one available: a longer clip gives the model more time to drift from the prompt.

For a spot longer than one clip, cut several shorter clips together in your editor. Check each placement's own length limits before you render the final.

How format choices affect billing

Seedance is billed per second of video returned, per model and resolution. What a clip uses from your prepaid balance is its duration in seconds multiplied by the per-second rate for that model and resolution. Failed jobs aren't billed.

• DurationBilled seconds follow the clip's length: a 10-second clip is billed as 10 seconds.
• ResolutionEach model has its own per-second rate for 480p and for 720p.
• ModelRates differ by model; seedance-2.0-mini is the lowest-cost option for drafts.
• Several placementsEach ratio is its own job, billed for its own seconds.
• RatesShared with early-access accounts. See pricing for how plans work.

For example, twelve 5-second drafts on seedance-2.0-mini at 480p are billed as 60 seconds at the mini 480p rate; one 15-second final on seedance-2.0 at 720p is billed as 15 seconds at the 2.0 720p rate. Most of the attempts happen at the lower rate, and only the approved version is rendered at full quality.

Setting format in a request

Duration is a top-level field; ratio, resolution and audio go in metadata.

{
  "model": "seedance-2.0",
  "prompt": "Tea bushes in rows across a misty hillside at sunrise, slow crane up",
  "duration": 10,
  "metadata": {
    "ratio": "21:9",
    "resolution": "720p",
    "generate_audio": false
  }
}

Send it to POST https://api.gotoramp.ai/v1/video/generations, then poll GET /v1/video/generations/{task_id}. Download the finished video within 24 hours; after that it isn't kept.

Related

• How to write Seedance video prompts
• Seedance models on GotoRamp
• Video API reference
• How billing works
• Rights and labeling checklist