Seedance 2.5 Flash API - What It Is, Price and How to Use It

Seedance 2.5 Flash is the faster version of Seedance 2.5 from ByteDance. It makes 4 to 30 second clips at 480p or 720p with sound in the same pass. It's live on Jantaris today: in Studio, over the API and in Claude via MCP. You pay per second of finished video, no subscription: from $0.264 per second at 480p, twice that at 720p.

Frame from my Seedance 2.5 Flash test: milk poured into a cup of coffee, 720p — My test: 5 s at 720p with sound, text only

What Seedance 2.5 Flash can do

Seedance 2.5 Flash has three modes:

Text to video. Describe the scene, get a shot with sound.
Image to video. Give it a first frame, optionally a last frame too, and it fills in the motion.
References. Up to 10 images, 5 clips and 5 audio tracks, referenced in the prompt as @Image 1, @Video 1, @Audio 1.

Length goes in one-second steps from 4 to 30 s. Aspect ratios: 16:9, 9:16, 4:3, 3:4, 1:1 and 21:9. Audio (speech, effects, music) is generated with the picture, and you can switch it off.

My test

I ran three 5-second clips at 720p from text only: a barista pouring milk into a cup, a cyclist on a coastal road at dusk, a paper boat in a forest stream. Each one was ready about 2.5 minutes after submitting, file download included. No stray text or odd artifacts, and the audio fit the scene: surf, trickling water, café noise. The clips are on the model page.

Seedance 2.5 Flash vs the full Seedance 2.5

ByteDance says Flash gets close to the full model at roughly twice the speed. The trade-offs:

no 1080p - Flash stops at 720p,
fewer references - 10 images instead of 30, 5 clips instead of 10,
no editing or extending of existing video.

At 720p Flash is about 10% cheaper per second; at 480p they cost practically the same. Full breakdown: Seedance 2.5 vs 2.5 Flash.

How to call it

bash

curl https://jantaris.com/v1/generate \
  -H "Authorization: Bearer $JANTARIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "seedance-2.5-flash", "input": {"prompt": "A paper boat drifts down a forest stream, low camera, water trickling", "resolution": "720p", "duration": 5}}'

The call returns a task right away. Collect the MP4 by polling the task or with a webhook. Full parameter list in the docs. In Claude, Claude Code, Codex and Cursor the model works through the MCP server.

FAQ

How much is a 10-second clip?

Ten times the per-second rate for your resolution. Reference clips add their own seconds. The calculator shows the exact amount, and failed generations are free.

Can I use a photo of a real person?

Yes, in image and reference mode, if you have that person's consent.

When should I use the full Seedance 2.5 instead?

For 1080p finals, projects with more than 10 reference images, and editing or extending existing footage.