SeeDream 4.0

What is SeeDream 4.0?#

SeeDream 4.0 is ByteDance's September 2025 entry in the 4.x image line and the default for day-to-day work in the family. It is tuned for near-photographic stills with strong character consistency across multiple calls, and the standout feature is dense small-text rendering: SeeDream 4.x produces legible body copy at 2K, useful for posters, packaging mocks, and infographic work where most image models still mangle the type. Up to six reference images, eight aspect ratios from 1:1 through 21:9, and resolutions at 2K (default) or 4K. Every call returns 4 images, so a single submission already covers an A/B sweep. The trade against the 5.0 line is reasoning. SeeDream 5.0 Lite handles vague intent ("make this more ecommerce") better. SeeDream 4.0 needs a clear prompt and rewards it with a cleaner result.

Key features of SeeDream 4.0#

Dense small-text rendering at 2K and 4K

Body copy stays legible inside the frame. Useful for posters, packaging mocks, and infographic work where the type has to read at thumb size as well as full bleed.

Up to 6 reference images per call

Six slots is enough for a multi-angle product setup or a multi-shot brand campaign. Strong material rendering on metal, fabric, and glass.

Eight aspect ratios, 2K or 4K

1:1 through 21:9 covers feed, vertical social, landscape banner, and ultra-wide cinematic. 2K for web, 4K for print and large-format display.

Returns 4 images per call

One submission produces four variants from the same prompt and references. Useful when you want to pick the strongest composition without paying for four separate runs.

Seed control for reproducible runs

Pass `seed` for the same prompt-and-reference combo to return the same outputs. Useful for A/B copy variants and version control on released assets.

Best for#

Use cases#

Build a print-ready campaign master at 4K with body copy that survives the press. Pass six product references on the same call to generate a multi-angle catalog set with consistent lighting and palette. Run a localization pass by holding references and seed steady while swapping the language string in the prompt; each market gets a matched layout. Sweep four compositional variants for a hero shot in a single submission, then pick the winner for upscale or hand-off to retouch.

API examples#

Call SeeDream 4.0 from any language by POSTing to /v1/tasks. Full parameter docs live at docs.unifically.com/models/image/bytedance/seedream-4.0.

curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "bytedance/seedream-4.0",
    "input": {
      "prompt": "A futuristic cityscape at night with neon lights",
      "aspect_ratio": "16:9",
      "resolution": "2k"
    }
  }'

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.