Seedream Historical Versions

Seedream 5.0 / 4.5 / 4.0 spec comparison, pricing differences, and migration guide. All three versions remain callable — pick by need, no breaking changes.

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.

Versions at a Glance

Version ID	Release Date (UTC+8)	APIYI Price	Status	Recommended Use
seedream-5-0-pro-260628	2026-06-28	$0.12 / request	🆕 Pro tier	Top image quality / complex instructions for professional work (~2 min per image)
seedream-5-0-260128	2026-01-28	$0.035 / image	✅ Recommended (latest)	Best overall experience, text rendering, png output
seedream-4-5-251128	2025-11-28	$0.04 / image	✅ Recommended	4K + strongest text rendering (posters, ads)
seedream-4-0-250828	2025-08-28	$0.03 / image	🟡 Maintained	4K + 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.

Per-version Specs

seedream-5-0-pro-260628 (5.0 Pro)

• Release date: 2026-06-28 (UTC+8); available on APIYI since 2026-07-19
• APIYI price: $0.12 / request (fixed per-request price, 1 image per request, ≈ ¥0.84 list). Officially the model uses two output-pixel price tiers (≤2.36M / >2.36M) plus a fee for reference images beyond the first; APIYI simplifies this to a flat per-request price with input-image fees included
• Resolution tiers: presets 1K / 2K (no 3K/4K presets) plus exact pixels WxH up to 4.19M total (max 2048×2048; at 16:9 the longest edge reaches 2720x1530 ≈ 2.7K, verified)
• Output format: png / jpeg
• Prompt optimization: standard / fast
• Highlights:
  • Strongest image quality and instruction following in the family; interactive editing (specify edit locations via coordinates, selection boxes, arrows)
  • Multi-image fusion officially supports up to 10 reference images
• Known limitations:
  • sequential_image_generation / stream are not accepted — any value (including "disabled") returns 400; omit both parameters entirely
  • Slow generation: consistently ~2 minutes per image (110-130s measured) — set client timeout ≥ 240s
  • 3.4× the unit price of 5.0-lite; use 5.0-lite for everyday work

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

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

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

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.

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)

Cost Comparison

Estimated by typical volume (before top-up bonuses; effective price drops to as low as 80% with bonuses):

Version	Unit Price	100 images	1,000 images	10,000 images
seedream-5-0-pro-260628	$0.12 / request	$12	$120	$1200
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)
• Top quality / complex instructions for professional work → 5.0-pro ($0.12/request + ~2 min per image — skip unless you need it)

Compatibility Matrix

Dimension	5.0-pro	5.0	4.5	4.0	Migration note
1K resolution tier	✅	❌	❌	✅	Migrating from 4.0 to 5.0-lite → switch 1K to 2K
4K resolution tier	❌	❌	✅	✅	Migrating from 4.5/4.0 to the 5.0 series → change the tier
output_format: "png"	✅	✅	❌	❌	Migrating from the 5.0 series → 4.5/4.0: transparency is lost
prompt_optimization: "fast"	✅	❌	❌	✅	5.0-lite / 4.5 don’t support fast — drop the parameter when switching
image array (multi-image fusion)	✅ (up to 10 explicit)	✅	✅ (up to 10 explicit)	✅	Identical protocol
sequential_image_generation	❌ (any value returns 400)	✅	✅	✅	Migrating to pro: remove the parameter entirely (including "disabled")
stream streaming	❌ (400 if passed)	✅	✅	✅	Migrating to pro: remove the parameter
Response fields (url / b64_json)	identical	identical	identical	identical	—
Billing	$0.12 per request	per image	per image	per image	—

Related Docs

• Seedream Overview
• Text-to-Image Playground
• Image Editing Playground
• Seedream 4.5 launch
• BytePlus official tutorial: docs.byteplus.com/en/docs/ModelArk/1824121