Head-to-head comparison

FLUX.2 Klein 9B vs. GPT Image 2.5 Flare

Compare shared capability tests, arena scores with documented retrieval dates, task-specific image pricing, and verified specifications. Research benchmarks, preference arenas, and our n = 1 samples remain separate.

shared result series: 6
shared sample prompts: 4
latest arena retrieval: 2026-09-22

First image modelSecond image model

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 Klein 9B and GPT Image 2.5 Flare
Attribute	FLUX.2 Klein 9B	GPT Image 2.5 Flare
Provider	Black Forest Labs	OpenAI
Released	January 2026	September 8, 2026
Access	API, local	API
Lifecycle	Weights released under the FLUX Non-Commercial License Status source	No separate lifecycle notice
Weights	Open weights	Proprietary
Parameters	9 billion	Not published
Maximum output	4 Megapixel	Not consistently published
Arena configuration	9B	No separate configuration named
Text-to-image price	$15 per 1,000 images	$210.7 per 1,000 images
Editing price	$17 per 1,000 images	$210.7 per 1,000 images
Technical source	Model sourceVerified 2026-09-24	Model sourceVerified 2026-09-22

FLUX.2 Klein 9BGPT Image 2.5 Flare

Text to Image ArenaUSD per 1,000 images at 1,024 × 1,024 pixels

FLUX.2 Klein 9B$15

GPT Image 2.5 Flare$210.7

Image Editing ArenaUSD per 1,000 images at 1,024 × 1,024 pixels

FLUX.2 Klein 9B$17

GPT Image 2.5 Flare$210.7

Key to the marks:better valuebetter, but not conclusivetie

Prompt adherence and specialist tests

Shared capability benchmarks

Both checkpoints completed the same four Gradually sample tasks. For each task, 30 archived first outputs are ranked in three differently ordered, model-blind passes. The published 0-100 value normalizes the mean rank. It must still be read as an n = 1 sample per model. No exact shared result from the integrated research benchmarks is available for this pair.

FLUX.2 Klein 9BGPT Image 2.5 Flare

Gradually sample test: Typography and layoutMean of three blind ranks across all 30 first outputs, n = 1 each

FLUX.2 Klein 9B10.3 / 100

GPT Image 2.5 Flare33.3 / 100

Gradually sample test: Product photographyMean of three blind ranks across all 30 first outputs, n = 1 each

FLUX.2 Klein 9B43.7 / 100

GPT Image 2.5 Flare43.7 / 100

Gradually sample test: Character and detailMean of three blind ranks across all 30 first outputs, n = 1 each

FLUX.2 Klein 9B28.7 / 100

GPT Image 2.5 Flare87.3 / 100

Gradually sample test: InfographicMean of three blind ranks across all 30 first outputs, n = 1 each

FLUX.2 Klein 9B14.9 / 100

GPT Image 2.5 Flare60.9 / 100

Key to the marks:better valuebetter, but not conclusivetie

Capability benchmark scores for FLUX.2 Klein 9B and GPT Image 2.5 Flare
Benchmark	FLUX.2 Klein 9B	GPT Image 2.5 Flare
Gradually sample test: Typography and layout	10.3 / 100 Mean rank: 27 (27 / 27 / 27) Five rubric scores Headline: 1.67 / 2 Subline: 0.67 / 2 Text control: 1 / 2 Visual brief: 1.67 / 2 Layout: 1 / 2	Higher blind-rank score33.3 / 100 Mean rank: 20.33 (21 / 17 / 23) Five rubric scores Headline: 1.67 / 2 Subline: 1.67 / 2 Text control: 1.67 / 2 Visual brief: 1.33 / 2 Layout: 1 / 2
Gradually sample test: Product photography	Tie43.7 / 100 Mean rank: 17.33 (13 / 19 / 20) Five rubric scores Subject: 1.67 / 2 Time: 1.33 / 2 Watch details: 1.67 / 2 Photography: 1.67 / 2 Exclusions: 1.67 / 2	Tie43.7 / 100 Mean rank: 17.33 (19 / 10 / 23) Five rubric scores Subject: 1.67 / 2 Time: 1.67 / 2 Watch details: 1 / 2 Photography: 1.67 / 2 Exclusions: 1.67 / 2
Gradually sample test: Character and detail	28.7 / 100 Mean rank: 21.67 (22 / 17 / 26) Five rubric scores Scene: 1 / 2 Wardrobe: 1 / 2 Anatomy: 1 / 2 Props: 1 / 2 Environment: 1 / 2	Higher blind-rank score87.3 / 100 Mean rank: 4.67 (2 / 1 / 11) Five rubric scores Scene: 1 / 2 Wardrobe: 1 / 2 Anatomy: 1 / 2 Props: 1 / 2 Environment: 1 / 2
Gradually sample test: Infographic	14.9 / 100 Mean rank: 25.67 (25 / 26 / 26) Five rubric scores Title: 1.67 / 2 Sequence: 1 / 2 Labels: 0.33 / 2 Diagram: 0.67 / 2 Clarity: 0.33 / 2	Higher blind-rank score60.9 / 100 Mean rank: 12.33 (12 / 11 / 14) Five rubric scores Title: 1.67 / 2 Sequence: 1.67 / 2 Labels: 1 / 2 Diagram: 1.67 / 2 Clarity: 1 / 2
Key to the marks:better valuebetter, but not conclusivetie

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.

2 shared result series

FLUX.2 Klein 9BGPT Image 2.5 Flare

Text to Image ArenaBlind preference from the same prompt, higher is better

FLUX.2 Klein 9B940 Elo

GPT Image 2.5 Flare1,190 Elo

Image Editing ArenaBlind preference from the same prompt, higher is better

FLUX.2 Klein 9B1,014 Elo

GPT Image 2.5 Flare1,161 Elo

Key to the marks:better valuebetter, but not conclusivetie

Arena benchmark scores for FLUX.2 Klein 9B and GPT Image 2.5 Flare
Benchmark	FLUX.2 Klein 9B	GPT Image 2.5 Flare	Source
Text to Image Arena	940 Elo Rank 75, 95% confidence interval: ±8, 10,360 ratings	Higher score1,190 Elo Rank 2, 95% confidence interval: ±9, 12,778 ratings	Artificial AnalysisRetrieved 2026-09-22
Image Editing Arena	1,014 Elo Rank 32, 95% confidence interval: ±9, 5,177 ratings	Higher score1,161 Elo Rank 2, 95% confidence interval: ±8, 17,496 ratings	Artificial AnalysisRetrieved 2026-09-22
Key to the marks:better valuebetter, but not conclusivetie

Visual comparison

Sample images

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

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 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
GPT Image 2.5 Flare. Provider OpenAI, 1024x1024, quality high, n=1, model ID gpt-image-2.5-flare, generated Sep 28, 2026, 8:53 PM. Source

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

Prompt SHA 256: 985a75b38642a9f0e5e0c0e0c67f1b7f67780d42bd2168fa24e9a7a7a94b0da6

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

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

GPT Image 2.5 Flare, image SHA 256: 85b17c41b19389cae3ea073ef582e6065a321d741978e772987d22e3ea3e3b08

GPT Image 2.5 Flare, request SHA 256: e1238a1112d45fcc4474ed85f5504be75304152073d5f320d732f5b8c431c759

Infographic

Numbers, labels, and visual organization

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 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
GPT Image 2.5 Flare. Provider OpenAI, 1024x1024, quality high, n=1, model ID gpt-image-2.5-flare, generated Sep 28, 2026, 8:53 PM. Source

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

Prompt SHA 256: ed65cb4e6a51e2336f8b149ad4cbb16e020f07d527ad94362e719d2dcf91d94f

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

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

GPT Image 2.5 Flare, image SHA 256: bc752abfce1c0d27b73e4084c3e7d82c4c0f71e0e5af97a80f4b24326cc4686e

GPT Image 2.5 Flare, request SHA 256: 8cd44a51b90bec6394d45d678bdfaa16e0fe014a237582999a2370b2e3db1c0b

Product photography

Materials, reflections, and fine details

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 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
GPT Image 2.5 Flare. Provider OpenAI, 1024x1024, quality high, n=1, model ID gpt-image-2.5-flare, generated Sep 28, 2026, 8:53 PM. Source

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

Prompt SHA 256: c67fd71e91304458a2feef5c91efa8677260fab0c0099a29a2c52cb579f5b2f3

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

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

GPT Image 2.5 Flare, image SHA 256: 69fedb7d635d1329c461ff1ee9e5cf8384119e218e3b3bdb93b9e11f728335d8

GPT Image 2.5 Flare, request SHA 256: a305103045fa5c2ede55b612333ab07c44dc0128f3d2faec67b8a117e52a82f0

Typography and layout

Legible text, hierarchy, and composition

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 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
GPT Image 2.5 Flare. Provider OpenAI, 1024x1024, quality high, n=1, model ID gpt-image-2.5-flare, generated Sep 28, 2026, 8:52 PM. Source

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

Prompt SHA 256: 2e012c3d14ee5dd02203a94f394ca80a5038cdebd6032b25a8b8a221f2255419

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

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

GPT Image 2.5 Flare, image SHA 256: cc90d54a99e1bad9e0cc8e4196746fb1d56a2fdd2a9ee101dbbf270ef5e4b6a8

GPT Image 2.5 Flare, request SHA 256: ec1fe63f04c319c731a93750e3d864df87e3f36142b33d88a3e1b5c5971aa2a5

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

Compare FLUX.2 Klein 9B and GPT Image 2.5 Flare with other important image models under the same evidence rules. Each page shows only exact shared measurements and samples.

View the complete image model comparison

FLUX.2 Klein 9B vs. GPT Image 2.5 Flare

Change image model selection

General specifications and task-specific pricing

Shared capability benchmarks

Shared arena benchmarks

Sample images

Character and detail

Infographic

Product photography

Typography and layout

An Elo score is not a verdict on creativity

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