FLUX 3 Image Kleinvs.Stable Diffusion 3.5 Medium

Which one is better?

In our own test, FLUX 3 Image Klein leads. Neither is in the arena. Neither has an API price.

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

FLUX 3 Image Klein: Typography and layout, first image from the fixed test run — FLUX 3 Image Klein86 out of 100

Stable Diffusion 3.5 Medium: Typography and layout, first image from the fixed test run — Stable Diffusion 3.5 Medium17 out of 100

Result for “Typography and layout”:FLUX 3 Image Klein 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

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

FLUX 3 Image Klein: openrouter, aspect ratio 1:1, resolution 1K, n=1, seed=provider random, actual cost $0.009000, generated Nov 1, 2026, 8:28 PM. Source

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

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

FLUX 3 Image Klein image SHA 256: b3331460097da628f405817301b99f206142350757be51bee5e406216ef8359f

Stable Diffusion 3.5 Medium image SHA 256: 6b8aa732e94479ad302904096c5031908141e4083ee099f080185aa04c2ea800

Infographic

FLUX 3 Image Klein: openrouter, aspect ratio 1:1, resolution 1K, n=1, seed=provider random, actual cost $0.009000, generated Nov 1, 2026, 8:28 PM. Source

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

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

FLUX 3 Image Klein image SHA 256: 8f6c2d4ea5814181f198e45caf6b561a650145fccf667ecb5cace92c1fc3bbcb

Stable Diffusion 3.5 Medium image SHA 256: 61b12e227431387098e51c6ce6d059be9d8df9c85263b994bee62602e2ddfd16

Product photography

FLUX 3 Image Klein: openrouter, aspect ratio 1:1, resolution 1K, n=1, seed=provider random, actual cost $0.009000, generated Nov 1, 2026, 8:28 PM. Source

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

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

FLUX 3 Image Klein image SHA 256: bafab00e86d3de8b29c6390b162e99291c84878c546246a95b5d47c6fe352fb9

Stable Diffusion 3.5 Medium image SHA 256: 2412a20e61c118ce7ab7ff83e285b96eb32d5c0f1171cc769e153db6655b8f67

Typography and layout

FLUX 3 Image Klein: openrouter, aspect ratio 1:1, resolution 1K, n=1, seed=provider random, actual cost $0.009000, generated Nov 1, 2026, 8:28 PM. Source

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

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

FLUX 3 Image Klein image SHA 256: 8f3f8cc9a1ab3c037f81a05bb3eec4e9a0129bad649347c4f40dc30c2870c0aa

Stable Diffusion 3.5 Medium image SHA 256: bc854c3269ea8bada6f764545f4a09abedc110219018c09f2fa5708a14d9af7e

The numbers at a glance

Arena ratingfrom votes by users · higher is better

n/a

FLUX 3 Image Klein

not in the arena

n/a

Stable Diffusion 3.5 Medium

not in the arena

GraduallyBenchour own rating, 0 to 100 · higher is better

FLUX 3 Image Klein

Rank 9 of 74

Stable Diffusion 3.5 Medium

Rank 69 of 74

Price per imagedollars through the API · lower is better

n/a

FLUX 3 Image Klein

no API price

n/a

Stable Diffusion 3.5 Medium

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.

FLUX 3 Image Klein

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

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.

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.

Kennzahl	FLUX 3 Image Klein	Stable Diffusion 3.5 Medium
Ratings
Arena ratingfrom votes by users, higher is better	n/a	n/a
Arena rank	n/a	n/a
Arena votesmore votes, a safer rating	n/a	n/a
GraduallyBenchour own rating, 0 to 100	71	16
GraduallyBench by task
Typography and layoutLegible text, hierarchy, and composition	86	17
Product photographyMaterials, reflections, and fine details	43	13
Character and detailAnatomy, clothing, and spatial consistency	82	16
InfographicNumbers, labels, and visual organization	74	20
API price
Per imagelower is better	n/a	n/a
100 images	n/a	n/a
Profile
Released	Oct 15, 2026	Oct 29, 2024
Weightsopen means: runs locally	open	open
Access	API, local	API, local
Parameters	5.6 billion	2.5 billion
Largest output	4K	not consistently published
Plans in Germanynaming exactly this model	n/a	n/a

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

Sources: FLUX 3 Image Klein model source (verified Nov 1, 2026) · Stable Diffusion 3.5 Medium 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 FLUX 3 Image Klein and Stable Diffusion 3.5 Medium from the same arena and category. Older model versions are not used as substitutes.

Compare another matchup

First image modelSecond image model

More matchups

Compare FLUX 3 Image Klein and Stable Diffusion 3.5 Medium with other important image models.

View the complete image model comparison

Same prompt, two images

The numbers at a glance

FLUX 3 Image Klein

Stable Diffusion 3.5 Medium

All data side by side

Arena ratings by category

No shared arena score in the stored snapshot

Compare another matchup

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