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Stable Diffusion 3.5 Largevs.FLUX1.1 [pro] Ultra

Which one is better?

In our own test both are on par. FLUX1.1 [pro] Ultra has no arena rating yet. Neither has an API price.

Test images

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

Stable Diffusion 3.5 Large: Character and detail, first image from the fixed test run
Stable Diffusion 3.5 Large23 out of 100
FLUX1.1 [pro] Ultra: Character and detail, first image from the fixed test run
FLUX1.1 [pro] Ultra45 out of 100

Result for “Character and detail”:FLUX1.1 [pro] Ultra slightly ahead

Prompt given to both modelsCreate a square cinematic full-body portrait of a fictional bicycle courier waiting under a transparent umbrella at a rainy tram stop in Hamburg at blue hour. She wears a mustard raincoat, navy trousers, red sneakers, a silver helmet, and carries a teal messenger bag. Keep both hands visible, render the bicycle correctly, use realistic wet-street reflections, and include no readable brand names.

What the rating looks at: Anatomy, clothing, and spatial consistency.

“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

Stable Diffusion 3.5 Large: fal, requested 1024x1024, n=1, seed=7087247023770270000, estimated cost $0.068157, generated Aug 14, 2026, 2:37 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

Stable Diffusion 3.5 Large image SHA 256: e748006fe56e442ad347e3f994f18b86ee1739f20dcee063aa7a03ee710c5d54

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

Infographic

Stable Diffusion 3.5 Large: fal, requested 1024x1024, n=1, seed=12166653711354006000, estimated cost $0.068157, generated Aug 14, 2026, 2:37 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

Stable Diffusion 3.5 Large image SHA 256: 4eb0fd741ef42e6d3fee4b1280cdfb098a0a04009b139051963895892e349f1e

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

Product photography

Stable Diffusion 3.5 Large: fal, requested 1024x1024, n=1, seed=13346308312015933000, estimated cost $0.068157, generated Aug 14, 2026, 2:37 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

Stable Diffusion 3.5 Large image SHA 256: ea9a7401dee8859ec2cb96af9f7ca29a177ef2202f52f629d8ce9f5839bd4061

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

Typography and layout

Stable Diffusion 3.5 Large: fal, requested 1024x1024, n=1, seed=16632333557910893000, estimated cost $0.068157, generated Aug 14, 2026, 2:37 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

Stable Diffusion 3.5 Large image SHA 256: e2994b1883a245b1c8c447957d121ea89d93aafff149029aa4e8507dbb769f9a

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

The numbers at a glance

Arena ratingfrom votes by users · higher is better
938

Stable Diffusion 3.5 Large

Rank 21 of 21

n/a

FLUX1.1 [pro] Ultra

not in the arena

GraduallyBenchour own rating, 0 to 100 · higher is better
27

Stable Diffusion 3.5 Large

Rank 87 of 108

31

FLUX1.1 [pro] Ultra

Rank 83 of 108

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

Stable Diffusion 3.5 Large

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.

Stable Diffusion 3.5 Large

Subscription
n/a No plan in Germany names exactly this model.
Via API
No API price known. Access: API, local.
License
Open weights.

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.

Arena rating (LMArena) from Nov 6, 2026 · 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.

KennzahlStable Diffusion 3.5 LargeFLUX1.1 [pro] Ultra
Ratings
Arena ratingfrom votes by users, higher is better938n/a
Arena rankRank 21 of 21n/a
Arena votesmore votes, a safer rating23,396n/a
GraduallyBenchour own rating, 0 to 1002731
GraduallyBench by task
Typography and layoutLegible text, hierarchy, and composition3122
Product photographyMaterials, reflections, and fine details1728
Character and detailAnatomy, clothing, and spatial consistency2345
InfographicNumbers, labels, and visual organization3928
API price
Per imagelower is bettern/an/a
100 imagesn/an/a
Profile
ReleasedOct 22, 2024n/a
Weightsopen means: runs locallyopenunknown
Lifecycleno noticeSeparate Ultra API route / Ultra mode; no independent checkpoint established
AccessAPI, localAPI
Parameters8.1 billionnot published
Largest output1 Megapixelnot consistently published
Plans in Germanynaming exactly this modeln/a12

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

Sources: Stable Diffusion 3.5 Large 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 Stable Diffusion 3.5 Large 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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