GPT Image 2.5 Sunburstvs.FLUX.2 Klein 9B

Which one is better?

GPT Image 2.5 Sunburst leads in both ratings: in our own test and in the arena. GPT Image 2.5 Sunburst costs 14 times as much per image.

Test images

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

GPT Image 2.5 Sunburst: Infographic, first image from the fixed test run — GPT Image 2.5 Sunburst97 out of 100

FLUX.2 Klein 9B: Infographic, first image from the fixed test run — FLUX.2 Klein 9B42 out of 100

Result for “Infographic”:GPT Image 2.5 Sunburst ahead

Prompt given to both modelsCreate 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.

What the rating looks at: Numbers, labels, and visual organization.

“Ahead”: better in all three rating rounds. “Slightly ahead”: a higher value, but not in every round.

Test protocol of the images

Each test attempt uses the same archived prompt and one request. The first output of that attempt counts. Repeats after technical test failures are disclosed for the affected images. 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

GPT Image 2.5 Sunburst: openai, 1024x1024, quality high, n=1, generated Sep 28, 2026, 8:51 PM. Source

FLUX.2 Klein 9B: fal, requested 1024x1024, n=1, seed=1587849924, estimated cost $0.006291, generated Aug 14, 2026, 1:52 PM. Source

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

GPT Image 2.5 Sunburst image SHA 256: 2bcd5e2358dbf9e2f11336ebf6c4a4a15e0a9a10261dd74378d40985ac68ec6d

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

Infographic

GPT Image 2.5 Sunburst: openai, 1024x1024, quality high, n=1, generated Sep 28, 2026, 8:52 PM. Source

FLUX.2 Klein 9B: fal, requested 1024x1024, n=1, seed=1082231541, estimated cost $0.006291, generated Aug 14, 2026, 1:52 PM. Source

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

GPT Image 2.5 Sunburst image SHA 256: 7dab94e5588be73aefe08f23f9d56ced4e2ddb2b29f754db41b057025cf34847

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

Product photography

GPT Image 2.5 Sunburst: openai, 1024x1024, quality high, n=1, generated Sep 28, 2026, 8:51 PM. Source

FLUX.2 Klein 9B: fal, requested 1024x1024, n=1, seed=1388538280, estimated cost $0.006291, generated Aug 14, 2026, 1:39 PM. Source

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

GPT Image 2.5 Sunburst image SHA 256: c648276704e06f7925f2325e8ffff0d9d0a9bd6c5bb4866785abac92ce97ff9a

FLUX.2 Klein 9B image SHA 256: e7208f19ccfb9b810b9648cb1861797b7155ad91933d1660059236cef413ebe0

Typography and layout

GPT Image 2.5 Sunburst: openai, 1024x1024, quality high, n=1, generated Sep 28, 2026, 8:50 PM. Source

FLUX.2 Klein 9B: fal, requested 1024x1024, n=1, seed=1340991019, estimated cost $0.006291, generated Aug 14, 2026, 2:41 PM. Source

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

GPT Image 2.5 Sunburst image SHA 256: fd6a3767ba8253869cb94d5346f025541dac924c2190df2c37b366b182986cf8

FLUX.2 Klein 9B image SHA 256: c5f23870e70f2245d24a3689f2579ceb770e5edf8c3c89b7d6ed7ae138f262f6

The numbers at a glance

Arena ratingfrom votes by users · higher is better

1,427

GPT Image 2.5 Sunburst

Rank 1 of 21

1,070

FLUX.2 Klein 9B

Rank 20 of 21

GraduallyBenchour own rating, 0 to 100 · higher is better

GPT Image 2.5 Sunburst

Rank 8 of 108

FLUX.2 Klein 9B

Rank 62 of 108

Price per imagedollars through the API · lower is better

$0.21

GPT Image 2.5 Sunburst

expensive

$0.015

FLUX.2 Klein 9B

cheap

Ranks among the 21 image models with an arena rating and the 108 with a GraduallyBench run; prices compared with 28 models with an API price.

GPT Image 2.5 Sunburst

Subscription: No OpenAI subscription includes this model. Through other providers from ≈ €6.39 a month (ElevenLabs Starter, with limited credits). 62 plans in Germany.
Via API: $0.21 per image, 100 images $21.07.

FLUX.2 Klein 9B

Subscription: n/a No plan in Germany names exactly this model.
Via API: $0.015 per image, 100 images $1.50.
License: Open weights, Weights released under the FLUX Non-Commercial License.

Subscriptions only count plans that name exactly this model. Subscription prices include VAT, API prices are in dollars.

Arena rating (LMArena) from Oct 28, 2026 · GraduallyBench from Nov 3, 2026 · API prices from Nov 3, 2026 · Subscription database from Sep 29, 2026 (35 days old)

All data side by side

The better value is bold. For ratings only when the gap is clear.

Kennzahl	GPT Image 2.5 Sunburst	FLUX.2 Klein 9B
Ratings
Arena ratingfrom votes by users, higher is better	1,427	1,070
Arena rank	Rank 1 of 21	Rank 20 of 21
Arena votesmore votes, a safer rating	40,323	150,695
GraduallyBenchour own rating, 0 to 100	75	50
GraduallyBench by task
Typography and layoutLegible text, hierarchy, and composition	54	32
Product photographyMaterials, reflections, and fine details	87	87
Character and detailAnatomy, clothing, and spatial consistency	64	39
InfographicNumbers, labels, and visual organization	97	42
API price
Per imagelower is better	$0.21	$0.015
100 images	$21.07	$1.50
Profile
Released	Sep 8, 2026	January 2026
Weightsopen means: runs locally	proprietary	openWeights released under the FLUX Non-Commercial License
Access	API	API, local
Parameters	not published	9 billion
Largest output	3,840 × 2,160 pixels	4 Megapixel
Plans in Germanynaming exactly this model	62	n/a

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

Sources: GPT Image 2.5 Sunburst model source (verified Sep 24, 2026) · FLUX.2 Klein 9B model source, status source (verified Sep 24, 2026)

Arena ratings by category

From blind votes on LMArena. “Ahead” means the lead is clear.

Arena rating per categoryfrom votes by users · higher is betterGPT Image 2.5 SunburstFLUX.2 Klein 9B

Text to Image Arena1,223930ahead

Image Editing Arena1,1991,016ahead

Text to Image: 3D modeling1,4161,078ahead

Text to Image: Art1,4091,079ahead

Text to Image: Cartoon1,4561,064ahead

Text to Image: Commercial design1,4191,070ahead

Text to Image: Overall1,4271,070ahead

Text to Image: Photorealism1,4331,091ahead

Text to Image: Portraits1,4611,092ahead

Text to Image: Text rendering1,4661,058ahead

Image Editing: Multi-image editing1,5211,212ahead

Image Editing: Overall1,5171,224ahead

Artificial Analysis from Nov 3, 2026 · LMArena from Oct 28, 2026

All individual values with sources

Rating	GPT Image 2.5 Sunburst	FLUX.2 Klein 9B	Source
Text to Image Arena	1,223	930	Artificial AnalysisRetrieved Nov 3, 2026
Image Editing Arena	1,199	1,016	Artificial AnalysisRetrieved Nov 3, 2026
Text to Image: 3D modeling	1,416	1,078	LMArenaRetrieved Oct 28, 2026
Text to Image: Art	1,409	1,079	LMArenaRetrieved Oct 28, 2026
Text to Image: Cartoon	1,456	1,064	LMArenaRetrieved Oct 28, 2026
Text to Image: Commercial design	1,419	1,070	LMArenaRetrieved Oct 28, 2026
Text to Image: Overall	1,427	1,070	LMArenaRetrieved Oct 28, 2026
Text to Image: Photorealism	1,433	1,091	LMArenaRetrieved Oct 28, 2026
Text to Image: Portraits	1,461	1,092	LMArenaRetrieved Oct 28, 2026
Text to Image: Text rendering	1,466	1,058	LMArenaRetrieved Oct 28, 2026
Image Editing: Multi-image editing	1,521	1,212	LMArenaRetrieved Oct 28, 2026
Image Editing: Overall	1,517	1,224	LMArenaRetrieved Oct 28, 2026

More comparisons with GPT Image 2.5 Sunburst and FLUX.2 Klein 9B

Compare GPT Image 2.5 Sunburst and FLUX.2 Klein 9B with the models people compare them with most often.

Compare another matchup

First image modelSecond image model

Predecessor and successor

PredecessorGPT Image 2.5 Sunburst vs. GPT Image 2Predecessor of GPT Image 2.5 Sunburst
GPT Image 2.5 Sunburst has no successor yet
No predecessor recorded for FLUX.2 Klein 9B
FLUX.2 Klein 9B has no successor yet

The most popular comparisons

Show all 12 comparisons