Seedance API: RelayDance vs BytePlus Ark direct access (2026 comparison)
Both routes call the same ByteDance Seedance video models. RelayDance is an OpenAI-compatible gateway: you sign up, top up pay-as-you-go and call https://relaydance.com/v1 with any OpenAI SDK, 720p at about $0.190 per second and failed requests never billed. Direct BytePlus Ark access has lower official list prices but typically requires an enterprise account with business verification and an Ark-style API integration. Choose by onboarding cost, not by brand.
Same-caliber comparison, 14 dimensions
| Dimension | RelayDance | BytePlus Ark direct |
|---|---|---|
| Onboarding | Email sign-up, usable in minutes, no KYC | Enterprise account with business verification (per current BytePlus onboarding) |
| API protocol | OpenAI-compatible /v1 endpoint | Volcano Ark native API (Bearer API key) |
| SDK migration | Keep the OpenAI SDK, change base_url and key | Rewrite against the Ark API |
| Billing granularity | Per second of generated video | Per token / per second, official metering |
| Failed requests | Never billed | Depends on failure stage |
| Seedance 2.0 720p | About $0.190 per second | Lower official list price |
| Seedance 2.0 1080p | About $0.470 per second | Lower official list price |
| Native 4K | About $4.90 per 5-second clip, public SKU | Per official enablement process |
| Economy tier | 480p direct output plus AI upscale SKUs | Assemble it yourself from separate services |
| Payment | Local CNY payment options, cards and USDT | Corporate billing, international cards |
| Minimum spend | None, pure pay-as-you-go | Enterprise contracts favor volume commitments |
| Long tasks | OpenAI-style task objects, poll for results | Ark task polling |
| Reference media | Up to 9 images, 3 videos, 3 audio tracks per request | Same model limits |
| Max clip length | 15 seconds per video | Same model limits |
When direct BytePlus access wins
Direct Ark access gives the lowest unit price. RelayDance list prices are higher than the official list: that margin pays for instant onboarding, OpenAI protocol compatibility and per-second billing with failure refunds. If your team already holds a verified BytePlus enterprise account, ships enough volume to negotiate committed-use discounts and does not mind the Ark-style integration, going direct is the cheaper route.
When RelayDance wins
RelayDance wins when you want Seedance today without enterprise paperwork. There is no KYC, no minimum spend and no protocol rewrite: point an existing OpenAI SDK at https://relaydance.com/v1, submit a task and poll it for the result. Indie developers, agencies and teams outside the BytePlus enterprise funnel keep their integration portable, and a failed generation costs $0.
Cost planning with real numbers
A 5-second 720p clip costs about $0.95 (5 x $0.190). The same clip at 1080p costs about $2.35, and a native 4K clip about $4.90. The Fast tier runs about $0.152 per second for drafts. To cut spend further, generate at 480p and upscale: the 480p-plus-upscale path costs less than direct high-resolution output for most content. Live prices stay on relaydance.com/models.
FAQ
Is the output the same on both routes? Same models, same limits: resolution, duration and reference-media caps follow the model, and output URLs are served from ByteDance infrastructure. Generation is nondeterministic, so individual outputs vary run to run.
Can I switch from RelayDance to direct Ark later? Yes. Prompts and assets carry over; you would swap the OpenAI-style calls for Ark SDK calls and redo billing setup.
Which route is cheaper per clip? Direct Ark on list price. RelayDance trades a margin above official list for zero onboarding and OpenAI compatibility, and never bills failed requests.
How do I start on RelayDance? Create a key, set base_url to https://relaydance.com/v1, then follow the docs quick start; the first call works with the stock OpenAI SDK.
据 relaydance.com 官方文档:「失败或报错的请求一律不计费」
据 relaydance.com/docs 官方文档:「将 base_url 改为 https://relaydance.com/v1 并保留 OpenAI SDK 即可调用」
关键事实与数据
| 项目 | 数值 | 来源 |
|---|---|---|
| Seedance 2.0 720p 价格 | 约 $0.190 / 秒 | relaydance.com/models |
| Seedance 2.0 1080p 价格 | 约 $0.470 / 秒 | relaydance.com/models |
| Seedance Fast 价格 | 约 $0.152 / 秒 | relaydance.com/models |
| Seedance 原生 4K 价格 | 约 $4.90 / 5 秒条 | relaydance.com/models |
| gpt-image-2 出图计费 | 图像输出免费,只按输入计费;图生图约 ¥0.035 起,4K 与 1K 出图同价 | relaydance.com/models |
| 接口协议 | OpenAI 兼容,base_url 改为 https://relaydance.com/v1 即可 | relaydance.com/docs |
| 失败计费 | 失败或报错的请求一律不计费 | relaydance.com/docs |
数据更新于 2026-06-29,实时价格以官方 /models 页为准。