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Seedream 4.0vs.FLUX1.1 [pro] Ultra

Which one is better?

In our own test, Seedream 4.0 leads. Neither is in the arena. Neither has an API price.

Test images

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

Seedream 4.0: Typography and layout, first image from the fixed test run
Seedream 4.065 out of 100
FLUX1.1 [pro] Ultra: Typography and layout, first image from the fixed test run
FLUX1.1 [pro] Ultra22 out of 100

Result for “Typography and layout”:Seedream 4.0 ahead

Prompt given to both modelsCreate a square editorial poster for an imaginary night train called MONDFALTER. Show the exact German headline MONDFALTER and the exact subline BERLIN NACH LISSABON. Use a restrained midnight-blue and warm-cream palette, one stylized moth, strong Swiss-grid typography, generous negative space, and no additional words or logos.

What the rating looks at: Legible text, hierarchy, and composition.

“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

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

FLUX1.1 [pro] Ultra: fal, aspect ratio 1:1; provider-native resolution, n=1, seed=3831910390, Fal exposes no resolution input; endpoint supports output up to 2K, Prompt enhancement disabled with enhance_prompt=false; default safety tolerance 2, estimated cost $0.060000, source 2048x2048, stored 1024x1024 (Lanczos3 downscale), generated Nov 2, 2026, 2:50 PM. Source

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

Seedream 4.0 image SHA 256: 81b5aa023fa252472878015448b5ee1cefcbc61844dd6cff98997685d7ab1511

FLUX1.1 [pro] Ultra image SHA 256: 0b97e1e3f33be2844c06cc18618fea633273ada7e9d6404f9769cdb8403ffbfc

Infographic

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

FLUX1.1 [pro] Ultra: fal, aspect ratio 1:1; provider-native resolution, n=1, seed=1664027293, Fal exposes no resolution input; endpoint supports output up to 2K, Prompt enhancement disabled with enhance_prompt=false; default safety tolerance 2, estimated cost $0.060000, source 2048x2048, stored 1024x1024 (Lanczos3 downscale), generated Nov 2, 2026, 2:50 PM. Source

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

Seedream 4.0 image SHA 256: 63dcddf4bf7bb58ea0c67eea96f2c71834158568f29ed3b7f2523b56a91e6526

FLUX1.1 [pro] Ultra image SHA 256: 2c7d24fcda220cf5eff966e1b857f11ad0e561f81ac9e4106ef1b4bd71686637

Product photography

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

FLUX1.1 [pro] Ultra: fal, aspect ratio 1:1; provider-native resolution, n=1, seed=291934417, Fal exposes no resolution input; endpoint supports output up to 2K, Prompt enhancement disabled with enhance_prompt=false; default safety tolerance 2, estimated cost $0.060000, source 2048x2048, stored 1024x1024 (Lanczos3 downscale), generated Nov 2, 2026, 2:49 PM. Source

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

Seedream 4.0 image SHA 256: 1fbad61d03b05e6cd8523e76409983e86c11c74fca2fa1a14d20f07f0d801519

FLUX1.1 [pro] Ultra image SHA 256: 7d497c35126a92de69af61e5721158a10f4e2acf88a8526dcdd0f8a9a571e028

Typography and layout

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

FLUX1.1 [pro] Ultra: fal, aspect ratio 1:1; provider-native resolution, n=1, seed=1909595532, Fal exposes no resolution input; endpoint supports output up to 2K, Prompt enhancement disabled with enhance_prompt=false; default safety tolerance 2, estimated cost $0.060000, source 2048x2048, stored 1024x1024 (Lanczos3 downscale), generated Nov 2, 2026, 2:49 PM. Source

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

Seedream 4.0 image SHA 256: 029be40f71522352246ad0de0de2e6c1ed2e45608f59c4f0e1be87b4dc2353c1

FLUX1.1 [pro] Ultra image SHA 256: 0dfeffb6c3489b9ac2e1ae9100793320fa4f5eab779269de7aff3a4b768595f3

The numbers at a glance

Arena ratingfrom votes by users · higher is better
n/a

Seedream 4.0

not in the arena

n/a

FLUX1.1 [pro] Ultra

not in the arena

GraduallyBenchour own rating, 0 to 100 · higher is better
62

Seedream 4.0

Rank 47 of 108

31

FLUX1.1 [pro] Ultra

Rank 83 of 108

Price per imagedollars through the API · lower is better
n/a

Seedream 4.0

no API price

n/a

FLUX1.1 [pro] Ultra

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.

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.

FLUX1.1 [pro] Ultra

Subscription
No Black Forest Labs subscription includes this model. Through other providers from ≈ €9.54 a month (Krea Basic, with limited credits). 12 plans in Germany.
Via API
No API price known. Access: API.
Weights
unknown.

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

GraduallyBench from Nov 3, 2026 · Subscription database from Sep 29, 2026 (38 days old)

All data side by side

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

KennzahlSeedream 4.0FLUX1.1 [pro] Ultra
Ratings
Arena ratingfrom votes by users, higher is bettern/an/a
Arena rankn/an/a
Arena votesmore votes, a safer ratingn/an/a
GraduallyBenchour own rating, 0 to 1006231
GraduallyBench by task
Typography and layoutLegible text, hierarchy, and composition6522
Product photographyMaterials, reflections, and fine details4428
Character and detailAnatomy, clothing, and spatial consistency7345
InfographicNumbers, labels, and visual organization6728
API price
Per imagelower is bettern/an/a
100 imagesn/an/a
Profile
ReleasedSeptember 2025n/a
Weightsopen means: runs locallyproprietaryunknown
Lifecycleno noticeSeparate Ultra API route / Ultra mode; no independent checkpoint established
AccessAPI, Web appAPI
Parametersnot publishednot published
Largest output4Knot consistently published
Plans in Germanynaming exactly this model1612

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

Sources: Seedream 4.0 model source (verified Aug 15, 2026) · FLUX1.1 [pro] Ultra model source, status source (verified Nov 1, 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 Seedream 4.0 and FLUX1.1 [pro] Ultra from the same arena and category. Older model versions are not used as substitutes.

More comparisons

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