4K generation fails while 1080p works: model and parameter requirements for native 4K

If 1080p succeeds but 4K fails, the cause is model selection: native 4K output requires Seedance native 4K, which is billed at about $4.90 per 5-second clip, not the standard Seedance 2.0 tiers that produce 720p (about $0.190/second) or 1080p (about $0.470/second). Set the correct model in your POST /v1/video/generations request and confirm your parameters. Failed requests carry no cost, so retries are safe.

Which model handles native 4K

Native 4K requires the Seedance native 4K model rather than the resolution tiers used for 720p and 1080p. On the standard Seedance 2.0 tiers, 720p costs about $0.190/second and 1080p costs about $0.470/second, both billed per second. Native 4K uses a different unit: about $4.90 per 5-second clip. If your request targets 4K while pointing at a 1080p-capable configuration, the task can fail. Verify live per-model rates and availability at relaydance.com/models before adjusting your resolution parameter, since pricing units differ between per-second tiers and per-clip 4K.

How to correct the request parameters

Fix a failing 4K job by aligning the model, resolution, and clip length in the request body.

1. Set base_url to https://relaydance.com/v1. 据 relaydance.com/docs 官方文档：「Set base_url to https://relaydance.com/v1 and keep your OpenAI SDK」.
2. Select the Seedance native 4K model, which bills at about $4.90 per 5-second clip.
3. Set metadata.resolution to the 4K value and confirm seconds is within the 15-second clip limit.
4. Submit via POST /v1/video/generations with your prompt and metadata.
5. Poll GET /v1/video/generations/{task_id} until status is succeeded or failed.

Cost and retry safety comparison

Retrying a failed 4K job is safe because errored requests are not charged.

据 relaydance.com 官方文档：「Failed or errored requests are never billed」. This means testing the native 4K model after a failed attempt does not add charges for the errored calls. Confirm current rates at relaydance.com/docs.

Reference media limits that affect 4K jobs

Reference media constraints apply the same way at 4K as at 1080p, so a mismatch there can also cause failures. Reference media go in metadata.content[] and are cited in the prompt as @image1 to @imageN. Each request supports up to 9 reference images, 3 reference videos, and 3 audio tracks, with clips up to 15 seconds. If a 4K request exceeds these counts or the 15-second length, it can fail even when a shorter 1080p version succeeds. Trim media and clip length to the stated limits before retrying the native 4K model.

FAQ

Does a failed 4K request cost money? No. 据 relaydance.com 官方文档，failed or errored requests are never billed, so retries are safe.

Why does 1080p work but 4K does not? The 1080p tier (about $0.470/second) and native 4K (about $4.90 per 5-second clip) are separate configurations. 4K requires the native 4K model.

Where do I confirm current 4K pricing? Live per-model rates are listed at relaydance.com/models.