ByteDance Seed · Image model

Seedream 4.5

bytedance-seed/seedream-4.5

Image

Released Dec 23, 2025

Seedream 4.5 is the latest in-house image generation model developed by ByteDance. Compared with Seedream 4.0, it delivers comprehensive improvements, especially in editing consistency, including better preservation of subject details,...

Specifications

Input: image, text
Output: image
Editing: yes, up to 14 reference images
Images per call: 1 to 4
Served by: Seed

Request options

Validated against these values; anything else returns 400 with the allowed list.

resolution: 1K, 2K, 4K
aspect_ratio: 1:1, 1:2, 2:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 9:19.5, 19.5:9, 9:20, 20:9, 9:21, 21:9, auto
seed: boolean

Use it

POST /api/v1/images · /images/edits · MCP generate_image · edit_image · full reference

curl https://omnirail.org/api/v1/images \
  -H "Authorization: Bearer $OMNIRAIL_KEY" -H "Content-Type: application/json" \
  -d '{"model":"bytedance-seed/seedream-4.5","prompt":"a lighthouse at dawn, 35mm film","aspect_ratio":"1:1"}'