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This page lists all Seedream versions still callable on APIYI. The three versions are active simultaneously, with fully compatible parameters — switch by changing only the model field. For the latest version and a general introduction, see Seedream Overview.

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Versions at a Glance

Version IDRelease Date (UTC+8)APIYI PriceStatusRecommended Use
seedream-5-0-2601282026-01-28$0.035 / image✅ Recommended (latest)Best overall experience, text rendering, png output
seedream-4-5-2511282025-11-28$0.04 / image✅ Recommended4K + strongest text rendering (posters, ads)
seedream-4-0-2508282025-08-28$0.03 / image🟡 Maintained4K + best price, only version supporting prompt fast mode
seedream-5-0-260128 can also be invoked with the alias seedream-5-0-lite-260128 — the official docs accept both model_id strings, with identical behavior.

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Per-version Specs

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seedream-5-0-260128 (5.0-lite)

  • Release date: 2026-01-28 (UTC+8)
  • APIYI price: $0.035 / image (≈ ¥0.245 list)
  • Resolution tiers: 2K / 3K (no 4K)
  • Output format: png / jpeg (only version with png output)
  • Prompt optimization: standard
  • Highlights:
    • Best overall experience; the most mature implementation of multi-image fusion / editing / batch sequence
    • Only version supporting png output (and therefore transparent backgrounds)
    • Mature streaming output (stream: true)
  • Known limits:
    • Resolution capped at 3K (~3072×3072). For 4K assets, use 4.5 / 4.0
  • Official docs: docs.byteplus.com/en/docs/ModelArk/1824121

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seedream-4-5-251128

  • Release date: 2025-11-28 (UTC+8)
  • APIYI price: $0.04 / image (≈ ¥0.28 list)
  • Resolution tiers: 2K / 4K
  • Output format: jpeg
  • Prompt optimization: standard
  • Highlights:
    • 1.2B-parameter unified generation-editing architecture
    • Text rendering breakthrough: small text remains crisp — best in class for posters, ads, UI screenshots
    • Multi-image fusion explicitly supports up to 10 reference images
    • Editing preserves lighting, tone, and natural facial detail
  • Known limits:
    • jpeg output only (no png, no transparency)
  • News article: Seedream 4.5 launch

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seedream-4-0-250828

  • Release date: 2025-08-28 (UTC+8)
  • APIYI price: $0.03 / image (≈ ¥0.21 list)
  • Resolution tiers: 1K / 2K / 4K (broadest coverage)
  • Output format: jpeg
  • Prompt optimization: standard / fast
  • Highlights:
    • Battle-tested stable version
    • Strong visual consistency, balanced 4K detail
    • Only version supporting prompt fast mode — faster generation for cost-sensitive scenarios
  • Known limits:
    • Text rendering weaker than 4.5
    • jpeg output only

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Migration Guidance

1

Assess differences

The three versions are fully compatible at the parameter level — change only the model field to switch. Double-check:
  • Whether your size tier is supported by the new version (5.0 has no 1K / 4K; 4.5 has no 1K; 4.0 has all)
  • Whether you depend on output_format: "png" (5.0 only)
  • Whether you use prompt_optimization: "fast" (4.0 only)
2

Run them side by side

Run the same prompt batch on the old and new versions, compare quality and cost. Validate with a small batch (10-20 images) before scaling.
3

Roll out gradually

Cut traffic in stages (10% / 50% / 100%). At each stage, observe quality, failure rate, and cost before scaling further.
4

Keep a fallback

Keep both old and new model configs in production code. If the new version misbehaves, flip back instantly. All three versions share unified billing — running both has no extra cost.

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Legacy Invocation Example

{/* Switching versions only changes the model field; other params are compatible */}
from openai import OpenAI

client = OpenAI(api_key="sk-your-api-key", base_url="https://api.apiyi.com/v1")

resp = client.images.generate(
    model="seedream-4-0-250828",   # change this line to switch to 4.5 / 5.0
    prompt="A serene mountain landscape at golden hour, snow-capped peaks, ultra detailed, 4K",
    size="4K",                      # NOTE: 5.0 does not support 4K — use 2K or 3K
    response_format="url",
    extra_body={
        "watermark": False,
    }
)

print(resp.data[0].url)

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Cost Comparison

Estimated by typical volume (before top-up bonuses; effective price drops to as low as 80% with bonuses):
VersionUnit Price100 images1,000 images10,000 images
seedream-5-0-260128$0.035$3.5$35$350
seedream-4-5-251128$0.04$4$40$400
seedream-4-0-250828$0.03$3$30$300
How to choose:
  • 4K assets + strong text → 4.5
  • 4K assets + best price → 4.0
  • Best overall / png output / transparent backgrounds → 5.0
  • Long-running stable batch production → 4.0 (proven, cheapest, fast prompt mode)

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Compatibility Matrix

Dimension5.04.54.0Migration note
1K resolution tier❌❌✅Migrating from 4.0 → switch 1K to 2K
4K resolution tier❌✅✅Migrating from 4.5/4.0 → 5.0: switch 4K to 2K or 3K
output_format: "png"✅❌❌Migrating from 5.0 → 4.5/4.0: transparency is lost
prompt_optimization: "fast"❌❌✅Migrating from 4.0: drop the parameter (defaults to standard)
image array (multi-image fusion)✅✅ (up to 10 explicit)✅All three: identical protocol
sequential_image_generation✅✅✅All three: identical protocol
stream streaming✅✅✅All three: identical protocol
Response fields (url / b64_json)identicalidenticalidentical—
Billingper imageper imageper image—