SeeDream 4.5

What is SeeDream 4.5?#

SeeDream 4.5 is the November 2025 mature checkpoint of ByteDance's 4.x image line. Use it when the same subject needs to appear across 30 images and look like the same subject every time. Reference-driven batches hold their character better than 4.0 or 4.1, and the dense-text rendering at 2K and above is the strongest in the family. Same parameter surface as 4.0 and 4.1: prompt, up to six references, eight aspect ratios from 1:1 through 21:9, resolutions at 2K (default) or 4K, optional seed, four images returned per call. If your work is brand campaigns, packaging, or character-driven content, 4.5 is the right tool. If you need vague-intent editing or PNG transparency support, look at SeeDream 5.0 Lite instead.

What's new in SeeDream 4.5#

Strongest character consistency in the 4.x line

Same actor across 30 images keeps facial structure, outfit, and styling stable. Useful for serial content, storytelling, and any campaign that asks the model to hold a likeness for a sustained run.

Tighter dense-text rendering

Body copy at 2K and 4K stays legible. Useful for posters with paragraphs of copy, infographic callouts, packaging mocks, and anything where the typography reads at thumb size.

Cleaner 4K output for print delivery

Mature checkpoint produces fewer artifacts at 4K than earlier 4.x versions. Production-ready at large size without a retouch pass.

Precision edits via reference

Pass an existing image as reference and prompt for a specific change. Edits stay surgical instead of rewriting the whole frame, useful for product variants and headline swaps.

Best for#

Use cases#

Run a serial character campaign by holding the same six references and seed across 30 calls. The actor reads as the same actor in every frame. Build a packaging mock with body copy at 2K and a press master at 4K from the same prompt, then deliver both without retouch on the type. Use precision-edit mode to swap the headline on an existing poster: pass the asset as a reference and prompt the change directly. Run brand campaign batches with palette and lighting locked across 100 calls; 4.5 holds steadier than 4.0 or 4.1 on long runs.

API examples#

Call SeeDream 4.5 from any language by POSTing to /v1/tasks. Full parameter docs live at docs.unifically.com/models/image/bytedance/seedream-4.5.

curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "bytedance/seedream-4.5",
    "input": {
      "prompt": "A magical forest with glowing mushrooms and fireflies",
      "resolution": "4k",
      "aspect_ratio": "1:1"
    }
  }'

Successful submission returns a task_id. Poll GET /v1/tasks/<task_id> or set a callback_url on the request to receive the four finished images.