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Stable Diffusion 3.5 Largevs.FLUX.2 Klein 4B

Which one is better?

In our own test both are on par. FLUX.2 Klein 4B has no arena rating yet. Neither has an API price.

Same prompt, two images

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

Stable Diffusion 3.5 Large: Product photography, first image from the fixed test run
Stable Diffusion 3.5 Large14 out of 100
FLUX.2 Klein 4B: Product photography, first image from the fixed test run
FLUX.2 Klein 4B54 out of 100

Result for “Product photography”:FLUX.2 Klein 4B 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

Both models receive the same archived prompt in exactly one request, and the first result counts. 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

FLUX.2 Klein 4B: fal, requested 1024x1024, n=1, seed=707400387, Fal's published 4B text-to-image endpoint; default four inference steps, estimated cost $0.005000, generated Nov 1, 2026, 9:01 PM. Source

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

Stable Diffusion 3.5 Large image SHA 256: e748006fe56e442ad347e3f994f18b86ee1739f20dcee063aa7a03ee710c5d54

FLUX.2 Klein 4B image SHA 256: 170cebb7cf75bc033a92371199812674f9cfa9641d5e9fb13947ccf892d4ed53

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

FLUX.2 Klein 4B: fal, requested 1024x1024, n=1, seed=290140178, Fal's published 4B text-to-image endpoint; default four inference steps, estimated cost $0.005000, generated Nov 1, 2026, 9:01 PM. Source

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

Stable Diffusion 3.5 Large image SHA 256: 4eb0fd741ef42e6d3fee4b1280cdfb098a0a04009b139051963895892e349f1e

FLUX.2 Klein 4B image SHA 256: 42b729a5a72207b5a92464f3ecf1713459ab1b105c3041c14b75c7622630015e

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

FLUX.2 Klein 4B: fal, requested 1024x1024, n=1, seed=1254275381, Fal's published 4B text-to-image endpoint; default four inference steps, estimated cost $0.005000, generated Nov 1, 2026, 9:00 PM. Source

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

Stable Diffusion 3.5 Large image SHA 256: ea9a7401dee8859ec2cb96af9f7ca29a177ef2202f52f629d8ce9f5839bd4061

FLUX.2 Klein 4B image SHA 256: 8fae4a7f6abb7467281c439dc93aa656031626f88c8a54f95f49850cbf045580

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

FLUX.2 Klein 4B: fal, requested 1024x1024, n=1, seed=1270698692, Fal's published 4B text-to-image endpoint; default four inference steps, estimated cost $0.005000, generated Nov 1, 2026, 9:00 PM. Source

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

Stable Diffusion 3.5 Large image SHA 256: e2994b1883a245b1c8c447957d121ea89d93aafff149029aa4e8507dbb769f9a

FLUX.2 Klein 4B image SHA 256: 7c2c3e30c20c98e90033087b2b95b151bddc3252dd4aed7092fcbca4ae4ea96e

The numbers at a glance

Arena ratingfrom votes by users · higher is better
938

Stable Diffusion 3.5 Large

Rank 22 of 22

n/a

FLUX.2 Klein 4B

not in the arena

GraduallyBenchour own rating, 0 to 100 · higher is better
18

Stable Diffusion 3.5 Large

Rank 67 of 74

37

FLUX.2 Klein 4B

Rank 55 of 74

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

Stable Diffusion 3.5 Large

no API price

n/a

FLUX.2 Klein 4B

no API price

Ranks among the 22 image models with an arena rating and the 74 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.

FLUX.2 Klein 4B

Subscription
No Black Forest Labs subscription includes this model. Through other providers from €6.83 a month (Poe Basic, with limited points). 12 plans in Germany.
Via API
No API price known. Access: API, local.
License
Open weights.

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 1, 2026 · Subscription database from Sep 29, 2026 (34 days old)

All data side by side

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

KennzahlStable Diffusion 3.5 LargeFLUX.2 Klein 4B
Ratings
Arena ratingfrom votes by users, higher is better938n/a
Arena rankRank 22 of 22n/a
Arena votesmore votes, a safer rating23,396n/a
GraduallyBenchour own rating, 0 to 1001837
GraduallyBench by task
Typography and layoutLegible text, hierarchy, and composition1121
Product photographyMaterials, reflections, and fine details1454
Character and detailAnatomy, clothing, and spatial consistency2353
InfographicNumbers, labels, and visual organization2319
API price
Per imagelower is bettern/an/a
100 imagesn/an/a
Profile
ReleasedOct 22, 2024n/a
Weightsopen means: runs locallyopenopen
AccessAPI, localAPI, local
Parameters8.1 billion4 billion
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) · FLUX.2 Klein 4B model 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 FLUX.2 Klein 4B from the same arena and category. Older model versions are not used as substitutes.

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