seedance21.io
seedance21.io is a Seedance-branded text-to-video and image-to-video workspace. Its homepage advertises short clips for social media, advertisements and product stories. The site presents a third-party workspace; its name and model labels do not establish that it is the official model developer.
Check which model the interface actually selects
The page uses Seedance 2.5 in its headline, but explains that current generation uses Seedance 2.0 controls. The displayed interface also shows Seedance 1.5 Pro with a four-second, 480p, 16:9 selection costing 16 credits. Those differences matter more than the headline when deciding what you are buying.
The FAQ describes 2.5 as an upgrade path and a discovery keyword, while other passages attribute native audio and multimodal capabilities to 2.5. Confirm the exact model and available options in the signed-in interface before treating those claims as a currently available feature set. Do not infer a release or an official partnership from the page's wording.
Direct a short clip with a clear reference
The described workflow accepts a prompt or reference images. The publisher recommends specifying the subject, motion, lighting and camera behavior, then reviewing the result and revising the prompt. A product image can provide a starting point, but inspect the generated object for altered logos or shapes.
The page lists aspect ratios including landscape, portrait and square, along with short clip durations. It also advertises resolutions of 480p, 720p and 1080p and synchronized audio. Because the page mixes model versions, check whether those controls apply to the model you select and how they change the credit cost. Start with a small test rather than assuming all advertised combinations are supported.
Confirm credits and rights before publishing
The homepage says daily free credits are available and paid plans add capacity. The pricing page does not list usable plan prices or allowances in its public text. Verify the account balance, checkout total and cost per generation before subscribing. The four-second example is one selection, not a universal price.
The publisher says videos made from your own prompts and assets may be used commercially and warns against infringing reference material. Read the terms that apply to the actual model and output before using a clip in client work. Obtain permission for recognizable people and protected assets in your references. A generated advertisement still needs review for accuracy and the rights to everything it depicts.