GPT Image 2.5 Sunburstvs.FLUX.2 Flex

Which one is better?

In our own test both are on par. In the arena, GPT Image 2.5 Sunburst leads. GPT Image 2.5 Sunburst costs 3.5 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: Typography and layout, first image from the fixed test run — GPT Image 2.5 Sunburst54 out of 100

FLUX.2 Flex: Typography and layout, first image from the fixed test run — FLUX.2 Flex98 out of 100

Result for “Typography and layout”:FLUX.2 Flex 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

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 Flex: together, 1024x1024, n=1, seed=provider random, provider default steps, generated Aug 14, 2026, 12:25 PM. Source

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

GPT Image 2.5 Sunburst image SHA 256: 2bcd5e2358dbf9e2f11336ebf6c4a4a15e0a9a10261dd74378d40985ac68ec6d

FLUX.2 Flex image SHA 256: 43b43d5782192d7284de2b824dd1caaaa6b25032d22fc3f8565d438b137089f3

Infographic

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

FLUX.2 Flex: together, 1024x1024, n=1, seed=provider random, provider default steps, generated Aug 14, 2026, 12:25 PM. Source

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

GPT Image 2.5 Sunburst image SHA 256: 7dab94e5588be73aefe08f23f9d56ced4e2ddb2b29f754db41b057025cf34847

FLUX.2 Flex image SHA 256: 105f60cdeb71a27021ffff1ad3c0ad919df4e5c74ad83b4628fbd64a8d795a09

Product photography

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

FLUX.2 Flex: together, 1024x1024, n=1, seed=provider random, provider default steps, generated Aug 14, 2026, 12:25 PM. Source

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

GPT Image 2.5 Sunburst image SHA 256: c648276704e06f7925f2325e8ffff0d9d0a9bd6c5bb4866785abac92ce97ff9a

FLUX.2 Flex image SHA 256: 9fef39b1500635ddbf78bcb8d3d9a68463ce952aa1fab89d12f6efe023907de7

Typography and layout

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

FLUX.2 Flex: together, 1024x1024, n=1, seed=provider random, provider default steps, generated Aug 14, 2026, 2:01 PM. Source

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

GPT Image 2.5 Sunburst image SHA 256: fd6a3767ba8253869cb94d5346f025541dac924c2190df2c37b366b182986cf8

FLUX.2 Flex image SHA 256: 324f87bf898593446a400abb43bd00eee015fa0a1dc160db0f864402fc0b38af

The numbers at a glance

Arena ratingfrom votes by users · higher is better

1,427

GPT Image 2.5 Sunburst

Rank 1 of 21

1,156

FLUX.2 Flex

Rank 16 of 21

GraduallyBenchour own rating, 0 to 100 · higher is better

GPT Image 2.5 Sunburst

Rank 8 of 108

FLUX.2 Flex

Rank 11 of 108

Price per imagedollars through the API · lower is better

$0.21

GPT Image 2.5 Sunburst

expensive

$0.06

FLUX.2 Flex

fairly 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 Flex

Subscription: No Black Forest Labs subscription includes this model. Through other providers from €6.83 a month (Poe Basic, with limited points). 26 plans in Germany.
Via API: $0.06 per image, 100 images $6.

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 Flex
Ratings
Arena ratingfrom votes by users, higher is better	1,427	1,156
Arena rank	Rank 1 of 21	Rank 16 of 21
Arena votesmore votes, a safer rating	40,323	156,876
GraduallyBenchour own rating, 0 to 100	75	73
GraduallyBench by task
Typography and layoutLegible text, hierarchy, and composition	54	98
Product photographyMaterials, reflections, and fine details	87	63
Character and detailAnatomy, clothing, and spatial consistency	64	75
InfographicNumbers, labels, and visual organization	97	57
API price
Per imagelower is better	$0.21	$0.06
100 images	$21.07	$6
Profile
Released	Sep 8, 2026	November 2025
Weightsopen means: runs locally	proprietary	proprietary
Access	API	API, Web app
Parameters	not published	not published
Largest output	3,840 × 2,160 pixels	4 Megapixel
Plans in Germanynaming exactly this model	62	26

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 Flex model 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 Flex

Text to Image Arena1,2231,026ahead

Image Editing Arena1,1991,002ahead

Text to Image: 3D modeling1,4161,173ahead

Text to Image: Art1,4091,155ahead

Text to Image: Cartoon1,4561,163ahead

Text to Image: Commercial design1,4191,172ahead

Text to Image: Overall1,4271,156ahead

Text to Image: Photorealism1,4331,145ahead

Text to Image: Portraits1,4611,144ahead

Text to Image: Text rendering1,4661,172ahead

Image Editing: Multi-image editing1,5211,234ahead

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 Flex	Source
Text to Image Arena	1,223	1,026	Artificial AnalysisRetrieved Nov 3, 2026
Image Editing Arena	1,199	1,002	Artificial AnalysisRetrieved Nov 3, 2026
Text to Image: 3D modeling	1,416	1,173	LMArenaRetrieved Oct 28, 2026
Text to Image: Art	1,409	1,155	LMArenaRetrieved Oct 28, 2026
Text to Image: Cartoon	1,456	1,163	LMArenaRetrieved Oct 28, 2026
Text to Image: Commercial design	1,419	1,172	LMArenaRetrieved Oct 28, 2026
Text to Image: Overall	1,427	1,156	LMArenaRetrieved Oct 28, 2026
Text to Image: Photorealism	1,433	1,145	LMArenaRetrieved Oct 28, 2026
Text to Image: Portraits	1,461	1,144	LMArenaRetrieved Oct 28, 2026
Text to Image: Text rendering	1,466	1,172	LMArenaRetrieved Oct 28, 2026
Image Editing: Multi-image editing	1,521	1,234	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 Flex

Compare GPT Image 2.5 Sunburst and FLUX.2 Flex 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 Flex
FLUX.2 Flex has no successor yet

The most popular comparisons

Show all 11 comparisons