Seedance 2.0 Spec Sheet: Max Length, Resolution, 4K, Aspect Ratios and Reference Limits

Seedance 2.0 generates clips of 4 to 15 seconds at 480p, 720p, 1080p or 4K, in six aspect ratios from 21:9 to 9:16, at 24 fps. Those are the limits ByteDance publishes for the dreamina-seedance-2-0-260128 model on BytePlus ModelArk (data checked 2026-10-08). 4K is exclusive to the full Seedance 2.0 model; Seedance 2.0 Fast and Seedance 2.0 Mini share the same 15-second ceiling but stop at 720p.

This page is a spec sheet, not a hands-on test. Every number below comes from ByteDance’s own documentation: the BytePlus ModelArk model list, the video generation tutorial (page stamp “Last updated: September 28, 2026”) and the Dreamina Seedance 2.0 series tutorial (page stamp “Last updated: September 29, 2026”), plus the consumer Dreamina Seedance 2.0 page where the consumer app differs. If you want prices rather than limits, the Seedance tiers guide covers the API rate card and the Seedance pricing review covers subscription credits.

Seedance 2.0 specs at a glance (data checked 2026-10-08)

Sources: BytePlus ModelArk model list and video generation tutorial, both read on 2026-10-08. The three 2.0 models share one input specification; the docs group them as “Dreamina Seedance 2.0 series”, and the 2.0 series tutorial describes the difference between them as a trade-off between generation quality and cost.

Two things in this table catch people out. First, Fast is not a cheaper route to 1080p: the tutorial’s pixel table carries the note “Dreamina Seedance 2.0 Fast and Dreamina Seedance 2.0 Mini do not support 1080p”. Second, the reference limits are per request, not per project. Each generation can use the full allowance again.

Seedance 2.0 maximum video length: 15 seconds per clip

The longest single Seedance 2.0 generation is 15 seconds. The video generation tutorial (checked 2026-10-08) sets the duration parameter “in whole seconds” with these ranges:

The -1 value is the one most people miss. The tutorial explains it directly: “A value of -1 enables intelligent duration selection, allowing the model to choose an appropriate video length within the supported range.” In practice that means you hand the length decision to the model and get something between 4 and 15 seconds back.

There is no fractional-second option on 2.0. The frames parameter, which converts to a duration at 24 frames per second and allows odd lengths, is documented for the Seedance 1.0 models only.

Getting past 15 seconds

The 15-second ceiling applies to one generation, not to a finished video. The 2.0 series tutorial lists video extension as a supported task: you can extend a clip forward or backward, or “stitch multiple video clips (up to 3 clips) into a coherent video”. Because each input video in a 2.0 request must be 2–15 seconds and all input videos together must stay within 15 seconds, extension is a way to chain shots, not a way to submit a long timeline in one call.

If a single uninterrupted take longer than 15 seconds is the requirement, the official answer is a different model. Seedance 2.5 is listed at 4–30 seconds on the same model list. Our multi-shot storytelling guide covers how to plan a sequence across several 15-second clips instead.

Seedance 2.0 resolution and 4K output

Seedance 2.0 has four output resolutions on the API: 480p, 720p, 1080p and 4K. The model list (checked 2026-10-08) gives the color depth for each:

The pixel table in the tutorial is blunt about who gets 4K: “Only Dreamina Seedance 2.0 supports 4K”. No other Seedance model on the BytePlus model list, including Seedance 2.5, lists a 4K option on the API.

What 4K changes besides pixels

Three practical differences come with the 4K setting, all documented by BytePlus as of 2026-10-08:

• Encoding: the 2.0 series tutorial states, “4K videos are output in H.265/HEVC encoding format. Some players or browsers may not support direct playback.” The same page links a FAQ on playback compatibility for 10-bit, H.265 files. If a 4K download will not play in your browser, check the codec before assuming the file is broken.
• Rate limits: non-4K Seedance 2.0 requests are capped at 600 requests per minute and 10 concurrent tasks for enterprise accounts, or 180 requests per minute and 3 concurrent tasks for individual accounts. At 4K, both account types drop to 15 requests per minute and 1 concurrent task. A 4K batch runs one job at a time.
• Cost: 4K is the most expensive Seedance 2.0 output per clip on the BytePlus pricing page, as recorded in our tiers guide (checked 2026-09-15). We keep prices there rather than repeating them on a spec sheet.

Where the “2K” figure came from

Older Seedance 2.0 coverage, including some earlier pages on this site, describes the model as “native 2K”. That was the launch-era description. Seedance 2.0 gained 4K output at the Volcano Engine FORCE conference on June 23, 2026, according to third-party launch coverage from The Decoder, and the current BytePlus documentation lists 4K with no 2K setting at all. For anything you build today, treat 480p / 720p / 1080p / 4K as the complete list.

Seedance 2.0 aspect ratios and exact pixel dimensions

The ratio parameter accepts 16:9, 4:3, 1:1, 3:4, 9:16, 21:9 and adaptive. Adaptive keeps the shape of your input instead of forcing a fixed ratio. ByteDance’s own 4K example in the 2.0 series tutorial uses "ratio": "adaptive" with a reference image.

Resolution and ratio together decide the exact frame size. These are the output dimensions the video generation tutorial lists for the Seedance 2.0 series (checked 2026-10-08):

A few details worth knowing before you set up an edit timeline:

• 480p is not 854×480 on Seedance 2.0. The 2.0 series renders 16:9 at 864×496; Seedance 2.5 uses 854×480 for the same setting. If you mix 480p drafts from both models in one project, expect a small scale step.
• 9:16 4K is 2160×3840, the vertical UHD frame size used for TikTok, Reels and Shorts uploads. Our platform formatting guide covers what each social platform does with it after upload.
• 21:9 is the only cinema-wide option. There is no 2.35:1 or 2.39:1 value in the ratio list, so a wider look has to be cropped in the edit.

How the model crops an image to your ratio

For image-to-video, the tutorial documents a center-crop rule. When the uploaded image does not match the requested ratio, the model crops it to that ratio, and the crop window is always centered on the original and stays fully inside it, with no black borders. The tutorial’s own advice is to set a ratio “as close as possible to the aspect ratio of the actual uploaded image”. If your subject sits near an edge, crop the source yourself first or switch to adaptive. Step-by-step setup is in our image-to-video tutorial.

Seedance 2.0 reference input limits

Seedance 2.0’s multimodal reference mode (the docs call it “omni reference”) is where most failed requests come from, because each file type has its own count, length, size and dimension window. Here is the full set for the 2.0 series, from the video generation tutorial’s Limitations section (checked 2026-10-08):

The whole request body is capped at 64 MB, and the docs advise against Base64 encoding for large files. Images and audio can be sent as a URL, a Base64 string or an asset ID; videos as a URL or an asset ID only.

Combinations that are allowed

The capability table in the tutorial lists image reference, video reference, and four mixed combinations for the 2.0 series: image + audio, image + video, video + audio, and image + video + audio. Audio-only reference is marked as not supported on Seedance 2.0, Fast and Mini, with the note “must be used with an image or video”. Seedance 2.5 is the only model in the table that accepts audio as the sole reference.

The real-face restriction

One limit is not about numbers. The tutorial states: “Dreamina Seedance 2.5 and Dreamina Seedance 2.0 series models do not support direct uploads of reference images or videos containing real human faces.” BytePlus documents separate routes for portrait work on a page titled “Create portrait videos with Dreamina Seedance models”. If a reference with a recognisable person fails while the same request with a landscape photo succeeds, this rule is the likely reason.

What the Dreamina app says

The consumer side describes the same allowance in one sentence. The Dreamina Seedance 2.0 page (read 2026-10-08) says you can “combine written prompts for your AI video with up to 12 reference resources, including 9 photos, 3 videos, and 3 audio clips.” The 9 / 3 / 3 split matches the API maximums. The Dreamina page does not repeat the 15-second totals for video and audio, the file-size caps or the real-face rule in its page text, so use the API figures above as the working limits. For audio-driven work specifically, see our Seedance native audio guide, and for video inputs the Seedance video-to-video guide.

Frame rate, file format, audio and watermark

The remaining output settings are short, but each one has a documented value as of 2026-10-08:

• Frame rate: 24 fps for every Seedance 2.0 model and resolution on the model list. Input videos may be 24 to 60 fps; the output is still 24.
• Container: .mp4 for all three 2.0 models. Seedance 2.5 is the only model on the list that also offers .mov.
• Generated audio: supported on 2.0, Fast and Mini through generate_audio.
• Last frame: all three can return the final frame of the clip (return_last_frame), which is the cleanest way to chain a next shot from an image-to-video request.
• Watermark: the watermark parameter set to true “Adds an AI-generated watermark in the lower-right corner of the video”; false leaves it off.
• Download window: “Video URLs are retained for 24 hours and can be downloaded up to 100 times.” Task records stay queryable for 7 days.

The 24-hour URL window matters more than it looks. If your pipeline polls a task, stores the URL and fetches the file later, a job that finishes on a Friday evening can be gone by Monday. Download on completion.

API spec vs the Dreamina app

The BytePlus documentation is the only official place that writes Seedance 2.0’s limits down as numbers. The Dreamina app exposes the same model through a settings panel, and its Seedance 2.0 page (read 2026-10-08) says you can “Customize your video duration, aspect ratio, and resolution”, without listing the ranges in the page text.

Where the two surfaces visibly differ, it is in features attached to Dreamina’s subscription plans rather than the model:

The plan list does not say how the 60 FPS or length extension is produced, and no BytePlus page we read on 2026-10-08 describes a 60 fps Seedance output. Treat those as Dreamina product features, not as Seedance 2.0 model specs. For which platforms carry Seedance 2.0 at all, see our Seedance 2.0 access guide.

How Seedance 2.0 compares with Fast, Mini and Seedance 2.5

The siblings differ in a handful of hard limits. From the same BytePlus model list and tutorial (checked 2026-10-08):

Read across the rows and the choice comes down to two limits. If you need 4K, only Seedance 2.0 has it. If you need more than 15 seconds in one take or more than 9 reference images, only Seedance 2.5 has it, at a 1080p ceiling on the API. Fast and Mini keep the full 2.0 input set and give up resolution, which makes them sensible for drafts you plan to re-render; the Seedance 2.0 Mini guide goes deeper on that workflow.

One status change appeared on the model list on 2026-10-08: Seedance 1.5 Pro (seedance-1-5-pro-251215) is now marked “Retired”, with dreamina-seedance-2-0-mini-260615 given as the recommended replacement. If an older integration of yours still calls 1.5 Pro, the 2.0 Mini limits on this page are the ones you are moving to. The order in which these versions shipped is in our Seedance version timeline.

Pre-flight checklist for a Seedance 2.0 request

Most rejected requests fail on a limit from the tables above. Before you submit, check:

1. Model and resolution match. 1080p and 4K need dreamina-seedance-2-0-260128; Fast and Mini will not accept them.
2. Duration is a whole number from 4 to 15, or -1.
3. Reference counts: no more than 9 images, 3 videos and 3 audio clips, with video and audio each totalling 15 seconds or less, and audio paired with at least one image or video.
4. File windows: images under 30 MB, videos up to 200 MB, audio up to 15 MB, sides between 300 and 6000 px, width-to-height ratio between 0.4 and 2.5, and a request body under 64 MB.
5. No real faces in direct uploads. Use BytePlus’s portrait routes instead.
6. 4K jobs queued one at a time, at no more than 15 requests per minute.
7. A downloader that runs on completion, since result URLs expire after 24 hours.

Request structure, authentication and polling are covered in our Seedance API guide; for a rough credit cost of a given length and resolution on consumer plans, use the credit calculator.

Sources and check dates

All figures on this page were read from the following official pages on 2026-10-08:

• BytePlus ModelArk model list: https://docs.byteplus.com/en/docs/ModelArk/1330310
• BytePlus ModelArk video generation tutorial (last updated September 28, 2026): https://docs.byteplus.com/en/docs/ModelArk/2298881
• BytePlus ModelArk Dreamina Seedance 2.0 series tutorial (last updated September 29, 2026): https://docs.byteplus.com/en/docs/ModelArk/2291680
• Dreamina Seedance 2.0 page: https://dreamina.capcut.com/tools/seedance-2-0

ByteDance updates these pages often, and Seedance 2.0’s own limits have already changed once since launch with the 4K upgrade. We re-check this sheet when the model list changes and update the date above.

SeedanceTips is an independent publication. We are not affiliated with ByteDance, Dreamina or BytePlus, and this page contains no affiliate links.