First, identify which “Seedance Fast” you mean
“Seedance Fast” is not a precise enough model name for choosing a production API. The sources use several distinct labels: Doubao Seedance 2.0 Fast, Doubao Seedance 1.0 Pro Fast, and a third-party listing called Seedance Fast. They do not establish that these names are interchangeable.
For Volcano Ark, the supplied documentation excerpt identifies Doubao Seedance 2.0 Fast with model ID doubao-seedance-2-0-fast-260128. It lists 480p and 720p output and six aspect ratios. These claims apply to that named Volcano Ark offering; they should not be generalized to every service listing a Seedance Fast model. (Volcano Ark model guide)
What the available documentation establishes
| Requirement | Volcano Ark: Doubao Seedance 2.0 Fast | Other captured claims |
|---|---|---|
| Model ID | doubao-seedance-2-0-fast-260128 |
Not established for the other listings here |
| Resolution | 480p or 720p | Treza also lists 480p or 720p for its own Seedance 2.0 Fast offering (Treza) |
| Aspect ratios | 21:9, 16:9, 4:3, 1:1, 3:4, and 9:16 | Treza says its offering has seven ratios but does not enumerate all seven; Sousaku lists six for its comparison (Treza, Sousaku) |
| Duration | Not confirmed in the captured Volcano Ark excerpt | Treza claims 4–15 seconds for its offering; Sousaku lists the same range for its Seedance 2.0 Fast comparison column. Neither establishes Volcano Ark’s allowed duration. |
| Audio, frame control, reference inputs, editing, or extension | Not established by the captured Volcano Ark excerpts for this model ID | Treza claims native audio, first/last-frame control, and reference images for its own hosted offering. Do not assume those claims apply to Volcano Ark. |
Sousaku’s third-party comparison gives a more specific feature list for its two listings. Its “Seedance Fast” column lists 480p, 720p, and 1080p; durations of 3, 4, 5, 6, 8, 10, and 12 seconds; and text-to-video and image-to-video. It marks audio and reference-images-to-video unsupported. Its separate “Seedance 2.0 Fast” column lists 480p and 720p; durations from 4 through 15 seconds; text-to-video and image-to-video; and audio and reference-images-to-video supported. The comparison marks video-to-video unsupported for both. These are Sousaku’s listing claims, not verified official specifications or a mapping to a particular provider’s model ID. (Sousaku comparison)
A separate CometAPI article describes Seedance 1.0 Pro Fast as a Seedance 1.0-family model and claims 720p or 1080p multi-shot clips. It does not establish that this is the same model as Seedance 2.0 Fast or provide a Volcano Ark model ID. (CometAPI)
The captured evidence does not verify a same-channel resolution comparison between Volcano Ark’s Fast and standard Seedance 2.0. Treza says its Fast offering is limited to 480p/720p and that full Seedance 2.0 also offers 1080p and 4K, but that is Treza’s product-page claim—not a verified Volcano Ark comparison. (Treza)
Choose by requirements—not by the word “Fast”
- If you need a documented Volcano Ark model identifier: the supplied Volcano Ark material identifies
doubao-seedance-2-0-fast-260128, with 480p/720p output and the six ratios listed above. - If you need 1080p or a 3-second clip: Sousaku’s comparison lists those options for its “Seedance Fast” listing, but not for its “Seedance 2.0 Fast” column. Confirm the exact provider and model before relying on this distinction; the listing is not mapped here to an official model ID.
- If you require audio, reference-image-to-video, or a duration above 12 seconds: Sousaku lists those for its “Seedance 2.0 Fast” column, with durations through 15 seconds, but not for its “Seedance Fast” column. Treza separately describes audio, first/last-frame control, and reference images for its own hosted Seedance 2.0 Fast offering. These claims are channel-specific and are not confirmation of Volcano Ark capabilities.
- If you require a particular duration, editing, or extension on Volcano Ark: the supplied Volcano Ark evidence does not establish those limits or capabilities for Fast. Confirm them in the selected provider’s model-specific documentation.
- If choosing on speed or visual quality: the captured comparisons provide no measured latency or reproducible quality results. A same-prompt comparison with matching inputs and settings can be your own evaluation, but it is not an existing benchmark.
Production API: the documented Volcano Ark route
The supplied Volcano Ark API material identifies a Beijing-region task-creation endpoint: POST https://ark.cn-beijing.volces.com/api/v3/contents/generations/tasks. The supplied video-generation tutorial describes an asynchronous workflow: poll GET /contents/generations/tasks/{id} until the task succeeds, or use a webhook; the completed result exposes the video at content.video_url. This supports describing a Volcano Ark task flow, not a direct API that is universal across Seedance providers. (Create a Video Generation Task, Video Generation Tutorial)
The captured excerpts do not establish the authentication header, a complete request-body schema applicable to this exact Fast model ID, accepted duration or audio parameters, or referenced-asset access requirements. For that reason, this guide does not present a copyable request as a verified working example. Consult the current Volcano Ark endpoint documentation for those details before implementing; the supplied material also does not establish availability of this Beijing-region route for every US or international account.
Treza’s hosted API path
Treza describes a different access channel: publish a pipeline containing a Seedance 2.0 Fast node as a versioned HTTP endpoint, then call its typed /invoke route, which enqueues a run and returns a run ID to poll. It also describes an OpenAI-compatible route. This is Treza’s hosted pipeline—not evidence of a direct ByteDance API or compatibility with Volcano Ark. The supplied Treza page does not establish endpoint URLs, authentication, payload schemas, or the polling route. (Treza Seedance 2.0 Fast)
Pricing and account conditions
The supplied Volcano Ark resource-pack excerpt lists a 1-million-token Seedance 2.0 Fast pack at CNY 22, with a nine-pack minimum and 90-day validity. Its supplied activation excerpt states an account-balance condition of CNY 200. These are Volcano Ark-specific terms; the captured excerpts do not establish the per-generation charge applicable to a particular request or all activation options. (Resource-pack rules, Activation and usage rules)
Bottom line
Identify the full model name and serving provider before comparing capabilities. For Volcano Ark, the supplied evidence identifies Doubao Seedance 2.0 Fast as doubao-seedance-2-0-fast-260128, with 480p/720p output and six listed aspect ratios, and describes an asynchronous task API flow. Sousaku’s separate “Seedance Fast” listing has different claimed options, but is not mapped here to an official model ID or another provider’s offering. Treza describes its own hosted API path. Verify model-specific capabilities, implementation details, and generation charges with the selected provider before production use.
Sources
Doubao Seedance 2.0 Series Tutorial — Volcano Ark
Seedance Fast vs Seedance 2.0 Fast — Sousaku AI
Seedance 1.0 Pro Fast — CometAPI
Create a Video Generation Task — Volcano Ark API
Video Generation Tutorial — Volcano Ark
Seedance 2.0–2.5 Model Resource Pack Rules
Seedance 2.5 and Seedance 2.0 Series Activation, Usage, and Refund Rules