How to control aspect ratio in Seedance: landscape, portrait and square output

Control aspect ratio in Seedance by setting the metadata.ratio field when you POST to /v1/video/generations. RelayDance uses an OpenAI-compatible API, so you send the model, prompt, seconds, and a metadata object that carries the ratio and resolution. The ratio value determines landscape, portrait, or square output. Poll GET /v1/video/generations/{task_id} until the status is succeeded or failed to retrieve the video url.

Where to set the aspect ratio in the request

Set the aspect ratio inside the metadata.ratio field of your video task request. Submit the task with POST /v1/video/generations, passing the model, prompt, and seconds at the top level, then place ratio and resolution inside the metadata object. Because the API is OpenAI-compatible, you keep your existing SDK. According to the official relaydance.com/docs, 「Set base_url to https://relaydance.com/v1 and keep your OpenAI SDK」. The same metadata object also accepts generate_audio, callback_url, and content[] for reference media. Reference images are cited in the prompt as @image1 to @imageN, with up to 9 reference images, 3 reference videos, and 3 audio tracks per request. Clips can run up to 15 seconds.

Landscape, portrait, and square orientations

Landscape, portrait, and square outputs are chosen by the ratio you pass, while the pixel dimensions follow the resolution field. Pair the ratio with a resolution such as 720p or 1080p to fix the final frame size. On Seedance 2.0, 720p output is billed at about $0.190 per second and 1080p at about $0.470 per second (source relaydance.com/models). For lower-cost work, Seedance Fast is about $0.152 per second, and native 4K is about $4.90 per 5-second clip. See live per-model rates at relaydance.com/models. Combine the orientation ratio with the resolution that matches your delivery target, then confirm both values before submitting the task.

Steps to generate a Seedance clip with a chosen ratio

Follow these numbered steps to produce a clip with a specific orientation.

1. Set your base URL to https://relaydance.com/v1 and authenticate with Authorization: Bearer YOUR_API_KEY (create keys at the console).
2. Send POST /v1/video/generations with the model, prompt, and seconds.
3. Inside the metadata object, set ratio for orientation and resolution for pixel size.
4. Add reference media in metadata.content[] and cite them in the prompt as @image1 to @imageN.
5. Poll GET /v1/video/generations/{task_id} until the status is succeeded or failed, then read the video url. Optionally set metadata.callback_url for webhook delivery.

See the full reference at relaydance.com/docs.

Resolution and price reference

The table below lists Seedance rates to help you match a resolution to your ratio.

Billing is pay-as-you-go per generated video. According to the official relaydance.com docs, 「Failed or errored requests are never billed」, so an invalid ratio or resolution that causes an error does not incur a charge.

FAQ

Which field controls the aspect ratio? The metadata.ratio field in the POST /v1/video/generations request controls orientation for landscape, portrait, or square output.

Am I charged if a request with an invalid ratio fails? No. Per relaydance.com, failed or errored requests are never billed.

How do I set resolution alongside the ratio? Set the resolution field in the metadata object; on Seedance 2.0, 720p is about $0.190 per second and 1080p is about $0.470 per second (source relaydance.com/models).