FLUX.2 Klein 4Bvs.FLUX.1 [dev]

Which one is better?

In our own test both are on par. 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.2 Klein 4B: Product photography, first image from the fixed test run — FLUX.2 Klein 4B54 out of 100

FLUX.1 [dev]: Product photography, first image from the fixed test run — FLUX.1 [dev]40 out of 100

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

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

FLUX.1 [dev]: fal, requested 1024x1024, n=1, seed=1386633789, estimated cost $0.025000, generated Nov 1, 2026, 9:00 PM. Source

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

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

FLUX.1 [dev] image SHA 256: 8cc425497844ab30bdb5f4b32b613219d01f1f21289d68fc198bb5980a3c6465

Infographic

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

FLUX.1 [dev]: fal, requested 1024x1024, n=1, seed=1094286267, estimated cost $0.025000, generated Nov 1, 2026, 9:00 PM. Source

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

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

FLUX.1 [dev] image SHA 256: 3d5c50031e545a82fe0617e724937b960d6e77c8371795f99fdf8037a2de8e9c

Product photography

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

FLUX.1 [dev]: fal, requested 1024x1024, n=1, seed=1029917942, estimated cost $0.025000, generated Nov 1, 2026, 8:59 PM. Source

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

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

FLUX.1 [dev] image SHA 256: 2932ee8c5af8a92655a9a9c4ad9ff782d366a51b9dad5553d84fe241d084d5c0

Typography and layout

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

FLUX.1 [dev]: fal, requested 1024x1024, n=1, seed=1184329997, estimated cost $0.025000, generated Nov 1, 2026, 8:59 PM. Source

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

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

FLUX.1 [dev] image SHA 256: 5a33abcfb19aa0d6d544ad7beb0ce59f51382a9418b5420edcc7aa553d578382

The numbers at a glance

Arena ratingfrom votes by users · higher is better

n/a

FLUX.2 Klein 4B

not in the arena

n/a

FLUX.1 [dev]

not in the arena

GraduallyBenchour own rating, 0 to 100 · higher is better

FLUX.2 Klein 4B

Rank 55 of 74

FLUX.1 [dev]

Rank 59 of 74

Price per imagedollars through the API · lower is better

n/a

FLUX.2 Klein 4B

no API price

n/a

FLUX.1 [dev]

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.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.

FLUX.1 [dev]

Subscription: No Black Forest Labs subscription includes this model. Through other providers from ≈ €9.59 a month (Krea Basic, with limited credits). 6 plans in Germany.
Via API: No API price known. Access: API, local.
License: Open weights, Older T2I checkpoint under a non-commercial license; hosted BFL API remains documented.

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.2 Klein 4B	FLUX.1 [dev]
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	37	29
GraduallyBench by task
Typography and layoutLegible text, hierarchy, and composition	21	7
Product photographyMaterials, reflections, and fine details	54	40
Character and detailAnatomy, clothing, and spatial consistency	53	40
InfographicNumbers, labels, and visual organization	19	27
API price
Per imagelower is better	n/a	n/a
100 images	n/a	n/a
Profile
Released	n/a	n/a
Weightsopen means: runs locally	open	openOlder T2I checkpoint under a non-commercial license; hosted BFL API remains documented
Access	API, local	API, local
Parameters	4 billion	12 billion
Largest output	not consistently published	not consistently published
Plans in Germanynaming exactly this model	12	6

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

Sources: FLUX.2 Klein 4B model source (verified Nov 1, 2026) · FLUX.1 [dev] 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 FLUX.2 Klein 4B and FLUX.1 [dev] from the same arena and category. Older model versions are not used as substitutes.

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First image modelSecond image model

More matchups

Compare FLUX.2 Klein 4B and FLUX.1 [dev] with other important image models.

View the complete image model comparison

Same prompt, two images

The numbers at a glance

FLUX.2 Klein 4B

FLUX.1 [dev]

All data side by side

Arena ratings by category

No shared arena score in the stored snapshot

Compare another matchup

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