GPT Image 2.5 Sunburstvs.Seedream 4.0

Which one is better?

In our own test both are on par. Seedream 4.0 has no arena rating yet. Seedream 4.0 has no API price.

Test images

Same task, the first image of each. The task with the biggest difference is preselected.

GPT Image 2.5 Sunburst: Product photography, first image from the fixed test run — GPT Image 2.5 Sunburst87 out of 100

Seedream 4.0: Product photography, first image from the fixed test run — Seedream 4.044 out of 100

Result for “Product photography”:GPT Image 2.5 Sunburst ahead

Prompt given to both modelsCreate a square premium product photograph of a brushed titanium wristwatch standing upright on dark green marble. The watch has a cream dial, thin black hands set to 10:10, twelve distinct hour markers, a realistic crown, and a dark brown leather strap. Soft window light from the left, controlled reflections, shallow depth of field, no text, no logo, no extra objects.

What the rating looks at: Materials, reflections, and fine details.

“Ahead”: better in all three rating rounds. “Slightly ahead”: a higher value, but not in every round.

Test protocol of the images

Each test attempt uses the same archived prompt and one request. The first output of that attempt counts. Repeats after technical test failures are disclosed for the affected images. Files are normalized to 1,024 × 1,024 pixels without cropping. Provider resolution, randomness, quality tier and prompt processing can still differ. The images are a practical visual test, not a reconstruction of the arena configuration.

Character and detail

GPT Image 2.5 Sunburst: openai, 1024x1024, quality high, n=1, generated Sep 28, 2026, 8:51 PM. Source

Seedream 4.0: together, 1024x1024, n=1, seed=provider random, provider default steps, generated Aug 14, 2026, 12:24 PM. Source

Protocol gradually-image-comparison-v1. Prompt SHA 256: 985a75b38642a9f0e5e0c0e0c67f1b7f67780d42bd2168fa24e9a7a7a94b0da6

GPT Image 2.5 Sunburst image SHA 256: 2bcd5e2358dbf9e2f11336ebf6c4a4a15e0a9a10261dd74378d40985ac68ec6d

Seedream 4.0 image SHA 256: 81b5aa023fa252472878015448b5ee1cefcbc61844dd6cff98997685d7ab1511

Infographic

GPT Image 2.5 Sunburst: openai, 1024x1024, quality high, n=1, generated Sep 28, 2026, 8:52 PM. Source

Seedream 4.0: together, 1024x1024, n=1, seed=provider random, provider default steps, generated Aug 14, 2026, 12:25 PM. Source

Protocol gradually-image-comparison-v1. Prompt SHA 256: ed65cb4e6a51e2336f8b149ad4cbb16e020f07d527ad94362e719d2dcf91d94f

GPT Image 2.5 Sunburst image SHA 256: 7dab94e5588be73aefe08f23f9d56ced4e2ddb2b29f754db41b057025cf34847

Seedream 4.0 image SHA 256: 63dcddf4bf7bb58ea0c67eea96f2c71834158568f29ed3b7f2523b56a91e6526

Product photography

GPT Image 2.5 Sunburst: openai, 1024x1024, quality high, n=1, generated Sep 28, 2026, 8:51 PM. Source

Seedream 4.0: together, 1024x1024, n=1, seed=provider random, provider default steps, generated Aug 14, 2026, 12:24 PM. Source

Protocol gradually-image-comparison-v1. Prompt SHA 256: c67fd71e91304458a2feef5c91efa8677260fab0c0099a29a2c52cb579f5b2f3

GPT Image 2.5 Sunburst image SHA 256: c648276704e06f7925f2325e8ffff0d9d0a9bd6c5bb4866785abac92ce97ff9a

Seedream 4.0 image SHA 256: 1fbad61d03b05e6cd8523e76409983e86c11c74fca2fa1a14d20f07f0d801519

Typography and layout

GPT Image 2.5 Sunburst: openai, 1024x1024, quality high, n=1, generated Sep 28, 2026, 8:50 PM. Source

Seedream 4.0: together, 1024x1024, n=1, seed=provider random, provider default steps, generated Aug 14, 2026, 2:01 PM. Source

Protocol gradually-image-comparison-v1. Prompt SHA 256: 2e012c3d14ee5dd02203a94f394ca80a5038cdebd6032b25a8b8a221f2255419

GPT Image 2.5 Sunburst image SHA 256: fd6a3767ba8253869cb94d5346f025541dac924c2190df2c37b366b182986cf8

Seedream 4.0 image SHA 256: 029be40f71522352246ad0de0de2e6c1ed2e45608f59c4f0e1be87b4dc2353c1

The numbers at a glance

Arena ratingfrom votes by users · higher is better

1,427

GPT Image 2.5 Sunburst

Rank 1 of 21

n/a

Seedream 4.0

not in the arena

GraduallyBenchour own rating, 0 to 100 · higher is better

GPT Image 2.5 Sunburst

Rank 8 of 108

Seedream 4.0

Rank 47 of 108

Price per imagedollars through the API · lower is better

$0.21

GPT Image 2.5 Sunburst

expensive

n/a

Seedream 4.0

no API price

Ranks among the 21 image models with an arena rating and the 108 with a GraduallyBench run; prices compared with 28 models with an API price.

GPT Image 2.5 Sunburst

Subscription: No OpenAI subscription includes this model. Through other providers from ≈ €6.39 a month (ElevenLabs Starter, with limited credits). 62 plans in Germany.
Via API: $0.21 per image, 100 images $21.07.

Seedream 4.0

Subscription: No ByteDance subscription includes this model. Through other providers from €6.83 a month (Poe Basic, with limited points). 16 plans in Germany.
Via API: No API price known. Access: API, Web app.

Subscriptions only count plans that name exactly this model. Subscription prices include VAT, API prices are in dollars.

Arena rating (LMArena) from Oct 28, 2026 · GraduallyBench from Nov 3, 2026 · API prices from Nov 3, 2026 · Subscription database from Sep 29, 2026 (35 days old)

All data side by side

The better value is bold. For ratings only when the gap is clear.

Kennzahl	GPT Image 2.5 Sunburst	Seedream 4.0
Ratings
Arena ratingfrom votes by users, higher is better	1,427	n/a
Arena rank	Rank 1 of 21	n/a
Arena votesmore votes, a safer rating	40,323	n/a
GraduallyBenchour own rating, 0 to 100	75	62
GraduallyBench by task
Typography and layoutLegible text, hierarchy, and composition	54	65
Product photographyMaterials, reflections, and fine details	87	44
Character and detailAnatomy, clothing, and spatial consistency	64	73
InfographicNumbers, labels, and visual organization	97	67
API price
Per imagelower is better	$0.21	n/a
100 images	$21.07	n/a
Profile
Released	Sep 8, 2026	September 2025
Weightsopen means: runs locally	proprietary	proprietary
Access	API	API, Web app
Parameters	not published	not published
Largest output	3,840 × 2,160 pixels	4K
Plans in Germanynaming exactly this model	62	16

API prices for one image at 1,024 × 1,024 pixels according to Artificial Analysis.

Sources: GPT Image 2.5 Sunburst model source (verified Sep 24, 2026) · Seedream 4.0 model source (verified Aug 15, 2026)

Arena ratings by category

From blind votes on LMArena. “Ahead” means the lead is clear.

No shared arena score in the stored snapshot

The stored benchmark database contains no measurement for GPT Image 2.5 Sunburst and Seedream 4.0 from the same arena and category. Older model versions are not used as substitutes.

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Predecessor and successor

PredecessorGPT Image 2.5 Sunburst vs. GPT Image 2Predecessor of GPT Image 2.5 Sunburst
GPT Image 2.5 Sunburst has no successor yet
Seedream 4.0 has no successor yet

Test images

The numbers at a glance

GPT Image 2.5 Sunburst

Seedream 4.0

All data side by side

Arena ratings by category

No shared arena score in the stored snapshot

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Predecessor and successor

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