Video came out shorter than requested: Seedance duration limits and the 15 second cap

If a Seedance video renders shorter than you asked for, the likely cause is the per-request duration limit: clips can run up to 15 seconds per request on RelayDance. The seconds field in your POST /v1/video/generations call controls length, and values above the 15 second cap cannot produce a longer clip. Verify the requested duration, resolution, and model before resubmitting through the OpenAI-compatible endpoint at https://relaydance.com/v1.

What the 15 second cap means for your request

The maximum clip length per request is 15 seconds, so any single generation cannot exceed that duration. When you submit a video task with POST /v1/video/generations, set the seconds value at or below 15; requesting more will not extend the output. If your result is shorter than the value you sent, check that the model and metadata (ratio, resolution) support the requested length. Reference media influence content but not the cap: you can attach up to 9 reference images, 3 reference videos, and 3 audio tracks per request, cited in the prompt as @image1 to @imageN. Review the live limits and per-model rates at https://relaydance.com/models.

How to check duration in your API call

Confirm the length by inspecting the seconds field and polling the task until it completes.

1. Set base_url to https://relaydance.com/v1 and keep your OpenAI SDK. According to the official relaydance.com/docs, 「Set base_url to https://relaydance.com/v1 and keep your OpenAI SDK」.
2. Submit POST /v1/video/generations with model, prompt, seconds (up to 15), and metadata.
3. Poll GET /v1/video/generations/{task_id} until status is succeeded or failed.
4. Read the video url from the succeeded result, or set metadata.callback_url for webhook delivery.

See https://relaydance.com/docs for the full flow.

Billing when a clip is short or fails

Billing is pay-as-you-go per generated video, and failed requests carry no charge. According to the official relaydance.com docs, 「Failed or errored requests are never billed」, so a rejected or errored task does not add to your cost. A successfully generated shorter clip is still billed per second at the model rate. Seedance 2.0 720p is about $0.190 per second and Seedance 2.0 1080p is about $0.470 per second, while Seedance Fast is about $0.152 per second. Seedance native 4K is priced at about $4.90 per 5-second clip. Confirm current rates at https://relaydance.com/models. Payments accepted include USDT and Stripe card.

Seedance rate comparison

The table below lists per-second and per-clip rates for common Seedance options.

FAQ

Can I request a clip longer than 15 seconds? No. Clips run up to 15 seconds per request, so set seconds at or below that value.

Am I charged if my video errors out? No, failed or errored requests are never billed; only successfully generated videos are charged.

How do I connect with my existing OpenAI SDK? Set base_url to https://relaydance.com/v1 and authenticate with Authorization: Bearer YOUR_API_KEY, using keys created at https://relaydance.com/console.