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Stable Diffusion 3.5 Mediumvs.FLUX.2 Klein 4B

Which one is better?

In our own test both are on par. Neither is in the arena. 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 Medium: Product photography, first image from the fixed test run
Stable Diffusion 3.5 Medium13 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 Medium: fal, requested 1024x1024, n=1, seed=provider random, estimated cost $0.020000, generated Nov 1, 2026, 9:17 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 Medium image SHA 256: 6b8aa732e94479ad302904096c5031908141e4083ee099f080185aa04c2ea800

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

Infographic

Stable Diffusion 3.5 Medium: fal, requested 1024x1024, n=1, seed=provider random, estimated cost $0.020000, generated Nov 1, 2026, 9:17 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 Medium image SHA 256: 61b12e227431387098e51c6ce6d059be9d8df9c85263b994bee62602e2ddfd16

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

Product photography

Stable Diffusion 3.5 Medium: fal, requested 1024x1024, n=1, seed=provider random, estimated cost $0.020000, generated Nov 1, 2026, 9:16 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 Medium image SHA 256: 2412a20e61c118ce7ab7ff83e285b96eb32d5c0f1171cc769e153db6655b8f67

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

Typography and layout

Stable Diffusion 3.5 Medium: fal, requested 1024x1024, n=1, seed=provider random, estimated cost $0.020000, generated Nov 1, 2026, 9:16 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 Medium image SHA 256: bc854c3269ea8bada6f764545f4a09abedc110219018c09f2fa5708a14d9af7e

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

The numbers at a glance

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

Stable Diffusion 3.5 Medium

not in the arena

n/a

FLUX.2 Klein 4B

not in the arena

GraduallyBenchour own rating, 0 to 100 · higher is better
16

Stable Diffusion 3.5 Medium

Rank 69 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 Medium

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 Medium

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.

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 MediumFLUX.2 Klein 4B
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 1001637
GraduallyBench by task
Typography and layoutLegible text, hierarchy, and composition1721
Product photographyMaterials, reflections, and fine details1354
Character and detailAnatomy, clothing, and spatial consistency1653
InfographicNumbers, labels, and visual organization2019
API price
Per imagelower is bettern/an/a
100 imagesn/an/a
Profile
ReleasedOct 29, 2024n/a
Weightsopen means: runs locallyopenopen
AccessAPI, localAPI, local
Parameters2.5 billion4 billion
Largest outputnot consistently publishednot 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 Medium model source (verified Nov 1, 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 Medium and FLUX.2 Klein 4B from the same arena and category. Older model versions are not used as substitutes.

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