Model Details
Seedance 2.0 Fast Image to Video animates a still you supply: the image becomes the first frame, the prompt describes what happens next, and the clip comes back with a matching soundtrack — dialogue, ambience, and sound effects generated together with the picture rather than dubbed on afterwards. It is the quick, lower-cost tier of Seedance 2.0: the same synchronized audio and the same 4 to 15 seconds at 24 fps, but capped at 720p, about a fifth cheaper per second, and noticeably faster to return. Prompts are understood in English, Chinese, Japanese, Indonesian, Spanish, and Portuguese.
## Best for - Bringing a product photo, poster, or packshot to life for an ad or social post - Animating illustrations, concept art, and character stills into moving shots - Adding camera movement — a slow push in, an orbit, a handheld drift — to a static frame - Trying several motion prompts on the same still cheaply before a final render
## Choose another model when - You need 1080p or the best picture quality in the family — use `bytedance/seedance-v2/image-to-video` - You want the cheapest clip and 720p is fine — `bytedance/seedance-v2-mini/image-to-video` is the lowest-cost tier - You have no source image and want the shot built from the prompt alone — use `bytedance/seedance-v2-fast/text-to-video` - You need to pin a last frame as well as a first, up to nine reference images, or a restyle of existing footage — top-tier only: `bytedance/seedance-v2/first-last-frame`, `bytedance/seedance-v2/reference-to-video`, `bytedance/seedance-v2/video-to-video` - You need runs reproducible from a fixed seed — there is no seed input, so repeat runs differ
## Tips - Describe the motion, not the picture — the still already fixes the subject, so spend the prompt on what moves and what is heard - Keep `aspect_ratio` on `adaptive` unless you want a crop; an explicit ratio that fights the source forces a re-frame - Source images should be 300–6000 px on a side, under 30 MB, and no more lopsided than about 2.5:1 - Set `generate_audio` to false for a silent clip; the price is the same either way - Put camera language in the prompt — there is no separate camera-lock control
## Limitations - Large motions away from the first frame can drift from the source subject's identity - Fine texture and small text in the source soften once the shot starts moving - Fast motion and crowds smear at 480p; multi-shot prompts drift in wardrobe and lighting
To run via the ModelRunner JavaScript client: ```js import { modelrunner } from "@modelrunner/client";
const result = await modelrunner.subscribe("bytedance/seedance-v2-fast/image-to-video", { input: { image: "https://media.modelrunner.ai/tjBYyLLFLpO4kt6L0HQTV.jpeg", prompt: "The wind rises and tugs at the trapped kite, its tail ribbon snapping loose and whipping sideways while the bare branches sway against the flat grey sky", resolution: "720p", aspect_ratio: "adaptive", duration: 6, generate_audio: true, }, }); ```


