Seedance 2.5

About

Seedance 2.5 is ByteDance's mainline video generation model, served through BytePlus ModelArk. It renders 4 to 30 second clips at a fixed 24 fps and generates native audio in the same pass.

It takes text on its own, a first frame or a first-and-last-frame pair for image-to-video, and multimodal references — a path that also covers video editing and video extension. Seedance 2.5 accepts up to 30 reference images, 10 reference videos, and 10 reference audio clips, roughly three times what Seedance 2.0 accepts.

Seedance 2.5 is an addition to the Seedance line, not a replacement. Seedance 2.0 stays the default: 2.5 doubles the maximum clip length and widens reference input, but it tops out at 720p, while 2.0 also renders 1080p and 4K. Pick 2.5 for length and references, and 2.0 when resolution decides the shot.

Pricing

Seedance 2.5 is a pay-as-you-go Premium Spark vendor model. Every clip uses purchased Spark, including for Sogni Unlimited members. Unlimited saves 5%; Unlimited Pro saves 10%.

Per-second Premium Spark rates: $0.300 per second at 720p and $0.134 per second at 480p.

Jobs that supply a reference video — video editing and video extension — use a lower vendor rate, so they cost less per second than text-to-video.

API

One Sogni API key reaches every model on the Supernet — call Seedance 2.5 with the exact model id.

import { SogniClient } from '@sogni-ai/sogni-client';

const client = await SogniClient.createInstance({
  appId: crypto.randomUUID(),
  apiKey: process.env.SOGNI_API_KEY,
  network: 'fast',
});

const project = await client.projects.create({
  type: 'video',
  modelId: 'seedance-2-5',
  positivePrompt: 'a slothicorn surfing a wave of liquid paint, slow push-in, cinematic',
  numberOfMedia: 1,
  duration: 5,
});

const [url] = await project.waitForCompletion();
console.log(url); // result link — download within 24h

# seedance-2-5 is addressable by id via the JavaScript SDK (see the JavaScript tab).
# The REST workflow API routes this family through its flagship alias instead:

curl https://api.sogni.ai/v1/creative-agent/workflows \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $SOGNI_API_KEY" \
  -d '{
    "input": {
      "title": "First render",
      "steps": [{
        "id": "step1",
        "toolName": "generate_video",
        "arguments": { "prompt": "a slothicorn surfing a wave of liquid paint, slow push-in, cinematic", "duration": 5 }
      }]
    },
    "confirm_cost": true
  }'

Addressable by id via the JavaScript SDK; the REST workflow API routes this family through its flagship alias. Full reference at docs.sogni.ai.