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Head-to-head comparison

FLUX.2 Flex vs. FLUX.2 Klein 9B

Compare arena scores with documented retrieval dates, task-specific image pricing, and verified specifications. Text-to-image generation and image editing are never blended into an artificial overall score.

12

shared result series

4

shared sample prompts

2026-08-16

latest arena retrieval

Change image model selection

Specifications and cost

General specifications and task-specific pricing

A model can have one price for generating new images and another for editing. Prices therefore remain tied to the corresponding arena configuration.

Specifications and pricing for FLUX.2 Flex and FLUX.2 Klein 9B
AttributeFLUX.2 FlexFLUX.2 Klein 9B
ProviderBlack Forest LabsBlack Forest Labs
ReleasedNovember 2025January 2026
AccessAPI, Web appAPI, local
LifecycleNo separate lifecycle noticeNo separate lifecycle notice
WeightsProprietaryOpen weights
ParametersNot published9 billion
Maximum output4 Megapixel4 Megapixel
Arena configurationFlex9B
Text-to-image price$60 per 1,000 images$15 per 1,000 images
Editing price$120 per 1,000 images$17 per 1,000 images
Technical sourceModel sourceVerified 2026-08-15Model sourceVerified 2026-08-15
FLUX.2 FlexFLUX.2 Klein 9B
Text to Image ArenaUSD per 1,000 images at 1,024 × 1,024 pixels
FLUX.2 Flex$60
FLUX.2 Klein 9B$15Lower price
Image Editing ArenaUSD per 1,000 images at 1,024 × 1,024 pixels
FLUX.2 Flex$120
FLUX.2 Klein 9B$17Lower price

Independent preference tests

Shared arena benchmarks

Artificial Analysis and Arena derive scores from blind comparisons. Raters see outputs for the same prompt and choose the image they prefer. Separate series cover text rendering, photorealism, portraits, art, commercial design, and image editing. Confidence intervals indicate how certain a measured lead is.

12 shared result series
FLUX.2 FlexFLUX.2 Klein 9B
Text to Image ArenaBlind preference from the same prompt, higher is better
FLUX.2 Flex1,220 EloHigher arena score
FLUX.2 Klein 9B1,149 Elo
Image Editing ArenaBlind preference from the same prompt, higher is better
FLUX.2 Flex1,164 Elo
FLUX.2 Klein 9B1,168 EloNo clear arena lead
Arena Text to Image: 3D modelingBlind preference from the same prompt, higher is better
FLUX.2 Flex1,171.967 arena pointsHigher arena score
FLUX.2 Klein 9B1,078.396 arena points
Arena Text to Image: ArtBlind preference from the same prompt, higher is better
FLUX.2 Flex1,155.954 arena pointsHigher arena score
FLUX.2 Klein 9B1,078.844 arena points
Arena Text to Image: CartoonBlind preference from the same prompt, higher is better
FLUX.2 Flex1,162.335 arena pointsHigher arena score
FLUX.2 Klein 9B1,063.975 arena points
Arena Text to Image: Commercial designBlind preference from the same prompt, higher is better
FLUX.2 Flex1,173.137 arena pointsHigher arena score
FLUX.2 Klein 9B1,069.649 arena points
Arena Text to Image: OverallBlind preference from the same prompt, higher is better
FLUX.2 Flex1,156.466 arena pointsHigher arena score
FLUX.2 Klein 9B1,069.517 arena points
Arena Text to Image: PhotorealismBlind preference from the same prompt, higher is better
FLUX.2 Flex1,146.683 arena pointsHigher arena score
FLUX.2 Klein 9B1,090.118 arena points
Arena Text to Image: PortraitsBlind preference from the same prompt, higher is better
FLUX.2 Flex1,144.533 arena pointsHigher arena score
FLUX.2 Klein 9B1,092.062 arena points
Arena Text to Image: Text renderingBlind preference from the same prompt, higher is better
FLUX.2 Flex1,172.004 arena pointsHigher arena score
FLUX.2 Klein 9B1,057.362 arena points
Arena Image Editing: Multi-image editingBlind preference from the same prompt, higher is better
FLUX.2 Flex1,233.804 arena pointsHigher arena score
FLUX.2 Klein 9B1,212.545 arena points
Arena Image Editing: OverallBlind preference from the same prompt, higher is better
FLUX.2 Flex1,225.241 arena pointsNo clear arena lead
FLUX.2 Klein 9B1,224.433 arena points
Arena benchmark scores for FLUX.2 Flex and FLUX.2 Klein 9B
BenchmarkFLUX.2 FlexFLUX.2 Klein 9BSource
Text to Image Arena
1,220 EloHigher arena score
Rank 18, 95% confidence interval: ±11, 4,481 ratings
1,149 Elo
Rank 60, 95% confidence interval: ±9, 7,939 ratings
Artificial AnalysisRetrieved 2026-08-15
Image Editing Arena
1,164 Elo
Rank 33, 95% confidence interval: ±7, 7,827 ratings
1,168 EloNo clear arena lead
Rank 30, 95% confidence interval: ±7, 11,020 ratings
Artificial AnalysisRetrieved 2026-08-15
Arena Text to Image: 3D modeling
1,171.967 arena pointsHigher arena score
Rank 19, 95% confidence interval: ±7.03, 15,066 ratings
1,078.396 arena points
Rank 54, 95% confidence interval: ±6.95, 13,814 ratings
ArenaRetrieved 2026-08-16
Arena Text to Image: Art
1,155.954 arena pointsHigher arena score
Rank 28, 95% confidence interval: ±6.38, 21,779 ratings
1,078.844 arena points
Rank 53, 95% confidence interval: ±6.28, 19,055 ratings
ArenaRetrieved 2026-08-16
Arena Text to Image: Cartoon
1,162.335 arena pointsHigher arena score
Rank 26, 95% confidence interval: ±5.15, 55,850 ratings
1,063.975 arena points
Rank 55, 95% confidence interval: ±5.01, 53,034 ratings
ArenaRetrieved 2026-08-16
Arena Text to Image: Commercial design
1,173.137 arena pointsHigher arena score
Rank 21, 95% confidence interval: ±4.95, 55,246 ratings
1,069.649 arena points
Rank 56, 95% confidence interval: ±4.59, 55,183 ratings
ArenaRetrieved 2026-08-16
Arena Text to Image: Overall
1,156.466 arena pointsHigher arena score
Rank 25, 95% confidence interval: ±3.42, 149,402 ratings
1,069.517 arena points
Rank 55, 95% confidence interval: ±3.25, 142,762 ratings
ArenaRetrieved 2026-08-16
Arena Text to Image: Photorealism
1,146.683 arena pointsHigher arena score
Rank 33, 95% confidence interval: ±4.87, 63,801 ratings
1,090.118 arena points
Rank 54, 95% confidence interval: ±4.7, 60,335 ratings
ArenaRetrieved 2026-08-16
Arena Text to Image: Portraits
1,144.533 arena pointsHigher arena score
Rank 34, 95% confidence interval: ±5.82, 33,696 ratings
1,092.062 arena points
Rank 55, 95% confidence interval: ±5.73, 32,758 ratings
ArenaRetrieved 2026-08-16
Arena Text to Image: Text rendering
1,172.004 arena pointsHigher arena score
Rank 22, 95% confidence interval: ±5.14, 49,969 ratings
1,057.362 arena points
Rank 56, 95% confidence interval: ±4.77, 51,643 ratings
ArenaRetrieved 2026-08-16
Arena Image Editing: Multi-image editing
1,233.804 arena pointsHigher arena score
Rank 22, 95% confidence interval: ±4.38, 125,392 ratings
1,212.545 arena points
Rank 25, 95% confidence interval: ±4.03, 147,846 ratings
ArenaRetrieved 2026-08-16
Arena Image Editing: Overall
1,225.241 arena pointsNo clear arena lead
Rank 34, 95% confidence interval: ±3.17, 415,923 ratings
1,224.433 arena points
Rank 35, 95% confidence interval: ±2.9, 507,400 ratings
ArenaRetrieved 2026-08-16

Visual comparison

Sample images from documented runs

Our images complement preference data, but do not replace it. The prompt, request count, and selection rule match. Provider resolution, quality tier, randomness, and prompt processing remain visible limitations, so this is not a fully controlled laboratory test.

Largely standardized comparison protocol. Both models receive the same archived prompt, 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. These images are a practical visual test, not a reconstruction of the arena configuration.

Character and detail

Anatomy, clothing, and spatial consistency

FLUX.2 Flex, Character and detail
FLUX.2 Flex
FLUX.2 Klein 9B, Character and detail
FLUX.2 Klein 9B
Prompt and settings

Create 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.

FLUX.2 Flex. Provider Together, 1024x1024, n=1, seed=provider random, provider default steps, model ID black-forest-labs/FLUX.2-flex, generated Aug 14, 2026, 12:25 PM. Source
FLUX.2 Klein 9B. Provider fal.ai, requested 1024x1024, n=1, seed=1587849924, estimated cost $0.006291, model ID fal-ai/flux-2/klein/9b, generated Aug 14, 2026, 1:52 PM. Source

Protocol gradually-image-comparison-v1, selection rule: first result.

Prompt SHA 256: 985a75b38642a9f0e5e0c0e0c67f1b7f67780d42bd2168fa24e9a7a7a94b0da6

FLUX.2 Flex, image SHA 256: 43b43d5782192d7284de2b824dd1caaaa6b25032d22fc3f8565d438b137089f3

FLUX.2 Flex, request SHA 256: fe5b22589e6505017dc44f4729b1bb60b15820ba3673354d03a69c8b82831953

FLUX.2 Klein 9B, image SHA 256: 84eceab680e59de6b9d4e68b3c21f6515ce093ff7d110992049e847570dd565f

FLUX.2 Klein 9B, request SHA 256: 5d005ee24926d68b7d2299b8ecbe4e14919f652761f6de2568a043f2a6258da0

Infographic

Numbers, labels, and visual organization

FLUX.2 Flex, Infographic
FLUX.2 Flex
FLUX.2 Klein 9B, Infographic
FLUX.2 Klein 9B
Prompt and settings

Create a square German infographic titled SO FUNKTIONIERT PHOTOSYNTHESE. Show exactly four numbered steps in this order: 1 LICHT, 2 WASSER, 3 CO₂, 4 ZUCKER + SAUERSTOFF. Use a clean editorial science style with one plant cross-section, simple arrows, high contrast, legible labels, and no other text.

FLUX.2 Flex. Provider Together, 1024x1024, n=1, seed=provider random, provider default steps, model ID black-forest-labs/FLUX.2-flex, generated Aug 14, 2026, 12:25 PM. Source
FLUX.2 Klein 9B. Provider fal.ai, requested 1024x1024, n=1, seed=1082231541, estimated cost $0.006291, model ID fal-ai/flux-2/klein/9b, generated Aug 14, 2026, 1:52 PM. Source

Protocol gradually-image-comparison-v1, selection rule: first result.

Prompt SHA 256: ed65cb4e6a51e2336f8b149ad4cbb16e020f07d527ad94362e719d2dcf91d94f

FLUX.2 Flex, image SHA 256: 105f60cdeb71a27021ffff1ad3c0ad919df4e5c74ad83b4628fbd64a8d795a09

FLUX.2 Flex, request SHA 256: 11d4ec056332340dc822c82021ef10c6a6aa92de6e44dc931a90b7cbb6f14146

FLUX.2 Klein 9B, image SHA 256: 1d2eb263ca5a25794a88df7bb04f5c13e10ed9a289371d1dcc7ed6d6e0a297e2

FLUX.2 Klein 9B, request SHA 256: 8b8014fc63f520d73ff57d3d8df5eae880097383167d44918b963f2830d09940

Product photography

Materials, reflections, and fine details

FLUX.2 Flex, Product photography
FLUX.2 Flex
FLUX.2 Klein 9B, Product photography
FLUX.2 Klein 9B
Prompt and settings

Create 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.

FLUX.2 Flex. Provider Together, 1024x1024, n=1, seed=provider random, provider default steps, model ID black-forest-labs/FLUX.2-flex, generated Aug 14, 2026, 12:25 PM. Source
FLUX.2 Klein 9B. Provider fal.ai, requested 1024x1024, n=1, seed=1388538280, estimated cost $0.006291, model ID fal-ai/flux-2/klein/9b, generated Aug 14, 2026, 1:39 PM. Source

Protocol gradually-image-comparison-v1, selection rule: first result.

Prompt SHA 256: c67fd71e91304458a2feef5c91efa8677260fab0c0099a29a2c52cb579f5b2f3

FLUX.2 Flex, image SHA 256: 9fef39b1500635ddbf78bcb8d3d9a68463ce952aa1fab89d12f6efe023907de7

FLUX.2 Flex, request SHA 256: 1c864c5e5d7f1e7008f15466fd0786f801ae94b17939b4f10de9a61c27766a59

FLUX.2 Klein 9B, image SHA 256: e7208f19ccfb9b810b9648cb1861797b7155ad91933d1660059236cef413ebe0

FLUX.2 Klein 9B, request SHA 256: 21e2c14d1b6315c30134e1390f531349608855d4ef1a87527e6d0ba57b2974ca

Typography and layout

Legible text, hierarchy, and composition

FLUX.2 Flex, Typography and layout
FLUX.2 Flex
FLUX.2 Klein 9B, Typography and layout
FLUX.2 Klein 9B
Prompt and settings

Create 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.

FLUX.2 Flex. Provider Together, 1024x1024, n=1, seed=provider random, provider default steps, model ID black-forest-labs/FLUX.2-flex, generated Aug 14, 2026, 2:01 PM. Source
FLUX.2 Klein 9B. Provider fal.ai, requested 1024x1024, n=1, seed=1340991019, estimated cost $0.006291, model ID fal-ai/flux-2/klein/9b, generated Aug 14, 2026, 2:41 PM. Source

Protocol gradually-image-comparison-v1, selection rule: first result.

Prompt SHA 256: 2e012c3d14ee5dd02203a94f394ca80a5038cdebd6032b25a8b8a221f2255419

FLUX.2 Flex, image SHA 256: 324f87bf898593446a400abb43bd00eee015fa0a1dc160db0f864402fc0b38af

FLUX.2 Flex, request SHA 256: a0aa716f2a302bdfa59820d2e2c27cc56f730e8e2e4d5b64223d29a6979e1475

FLUX.2 Klein 9B, image SHA 256: c5f23870e70f2245d24a3689f2579ceb770e5edf8c3c89b7d6ed7ae138f262f6

FLUX.2 Klein 9B, request SHA 256: 530872e813e988ba95025956a3743c6111120af963d90b8970a8bf3eced5547b

How to read this comparison

An Elo score is not a verdict on creativity

A higher arena score means this specific configuration was preferred more often in blind comparisons.

Typography, character consistency, local execution, licensing, and price may matter more to your workload than overall visual appeal.

Prices cover 1,000 images at 1,024 × 1,024 pixels using settings documented by Artificial Analysis. Subscriptions and special rates are excluded.

More matchups

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View the complete image model comparison