GPT Image 2.5 Sunburstvs.Chroma1-HD
Which one is better?
In our own test, GPT Image 2.5 Sunburst leads. Chroma1-HD has no arena rating yet. Chroma1-HD has no API price.
Test images
Same task, the first image of each. The task with the biggest difference is preselected.
Result for “Infographic”:GPT Image 2.5 Sunburst ahead
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
Chroma1-HD: manual, local PyTorch 2.13.0, Diffusers 0.36.0; lodestones/Chroma1-HD@0e0c60ece1e82b17cb7f77342d765ba5024c40c0; native 1024x1024, 1:1; one request, first output; steps=40, guidance=3.0, seed=4845693986590311438; mps for text encoder and denoising; cpu for native VAE decode; bfloat16 for text encoder and transformer; float32 for VAE, generated Nov 2, 2026, 7:16 PM. Source
Protocol gradually-image-comparison-v1. Prompt SHA 256: 985a75b38642a9f0e5e0c0e0c67f1b7f67780d42bd2168fa24e9a7a7a94b0da6
GPT Image 2.5 Sunburst image SHA 256: 2bcd5e2358dbf9e2f11336ebf6c4a4a15e0a9a10261dd74378d40985ac68ec6d
Chroma1-HD image SHA 256: 7ca51c510884638a4d8c09d0e361e2bf0328c466d36ec4235f5305580dc10a8a
Infographic
GPT Image 2.5 Sunburst: openai, 1024x1024, quality high, n=1, generated Sep 28, 2026, 8:52 PM. Source
Chroma1-HD: manual, local PyTorch 2.13.0, Diffusers 0.36.0; lodestones/Chroma1-HD@0e0c60ece1e82b17cb7f77342d765ba5024c40c0; native 1024x1024, 1:1; one request, first output; steps=40, guidance=3.0, seed=3726635088695005336; mps for text encoder and denoising; cpu for native VAE decode; bfloat16 for text encoder and transformer; float32 for VAE, generated Nov 2, 2026, 7:22 PM. Source
Protocol gradually-image-comparison-v1. Prompt SHA 256: ed65cb4e6a51e2336f8b149ad4cbb16e020f07d527ad94362e719d2dcf91d94f
GPT Image 2.5 Sunburst image SHA 256: 7dab94e5588be73aefe08f23f9d56ced4e2ddb2b29f754db41b057025cf34847
Chroma1-HD image SHA 256: 834ab94e5514295d56b66f606572d348fc4b5d1cdeba5874921c79c00774c76a
Product photography
GPT Image 2.5 Sunburst: openai, 1024x1024, quality high, n=1, generated Sep 28, 2026, 8:51 PM. Source
Chroma1-HD: manual, local PyTorch 2.13.0, Diffusers 0.36.0; lodestones/Chroma1-HD@0e0c60ece1e82b17cb7f77342d765ba5024c40c0; native 1024x1024, 1:1; one request, first output; steps=40, guidance=3.0, seed=7965145008513162443; mps for text encoder and denoising; cpu for native VAE decode; bfloat16 for text encoder and transformer; float32 for VAE, generated Nov 2, 2026, 7:10 PM. Source
Protocol gradually-image-comparison-v1. Prompt SHA 256: c67fd71e91304458a2feef5c91efa8677260fab0c0099a29a2c52cb579f5b2f3
GPT Image 2.5 Sunburst image SHA 256: c648276704e06f7925f2325e8ffff0d9d0a9bd6c5bb4866785abac92ce97ff9a
Chroma1-HD image SHA 256: 8a0ebbb527f4db84a42a98a256333b00b4dc5ffae699a31b694f36bf34613e4b
Typography and layout
GPT Image 2.5 Sunburst: openai, 1024x1024, quality high, n=1, generated Sep 28, 2026, 8:50 PM. Source
Chroma1-HD: manual, local PyTorch 2.13.0, Diffusers 0.36.0; lodestones/Chroma1-HD@0e0c60ece1e82b17cb7f77342d765ba5024c40c0; native 1024x1024, 1:1; one request, first output; steps=40, guidance=3.0, seed=2582507270187158929; mps for text encoder and denoising; cpu for native VAE decode; bfloat16 for text encoder and transformer; float32 for VAE, generated Nov 2, 2026, 7:04 PM. Source
Protocol gradually-image-comparison-v1. Prompt SHA 256: 2e012c3d14ee5dd02203a94f394ca80a5038cdebd6032b25a8b8a221f2255419
GPT Image 2.5 Sunburst image SHA 256: fd6a3767ba8253869cb94d5346f025541dac924c2190df2c37b366b182986cf8
Chroma1-HD image SHA 256: d0ccb26f1a27cc3142c3c669b3e05ed7bb568b58706a237e7e34b3bbb68a9cc5
The numbers at a glance
GPT Image 2.5 Sunburst
Rank 1 of 21
Chroma1-HD
not in the arena
GPT Image 2.5 Sunburst
Rank 8 of 108
Chroma1-HD
Rank 94 of 108
GPT Image 2.5 Sunburst
expensive
Chroma1-HD
no API price
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 ≈ €6.36 a month (ElevenLabs Starter, with limited credits). 62 plans in Germany.
- Via API
- $0.21 per image, 100 images $21.07.
Chroma1-HD
- Subscription
- n/a No plan in Germany names exactly this model.
- Via API
- No API price known. Access: local.
- License
- Open weights.
Subscriptions only count plans that name exactly this model. Subscription prices include VAT, API prices are in dollars.
Arena rating (LMArena) from Nov 6, 2026 · GraduallyBench from Nov 3, 2026 · API prices from Nov 6, 2026 · Subscription database from Sep 29, 2026 (38 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 | Chroma1-HD |
|---|---|---|
| Ratings | ||
| Arena ratingfrom votes by users, higher is better | 1,427 | n/a |
| Arena rank | Rank 1 of 21 | n/a |
| Arena votesmore votes, a safer rating | 54,913 | n/a |
| GraduallyBenchour own rating, 0 to 100 | 75 | 23 |
| GraduallyBench by task | ||
| Typography and layoutLegible text, hierarchy, and composition | 54 | 36 |
| Product photographyMaterials, reflections, and fine details | 87 | 16 |
| Character and detailAnatomy, clothing, and spatial consistency | 64 | 17 |
| InfographicNumbers, labels, and visual organization | 97 | 22 |
| API price | ||
| Per imagelower is better | $0.21 | n/a |
| 100 images | $21.07 | n/a |
| Profile | ||
| Released | Sep 8, 2026 | n/a |
| Weightsopen means: runs locally | proprietary | open |
| Access | API | local |
| Parameters | not published | 8.9 billion |
| Largest output | 3,840 × 2,160 pixels | not consistently published |
| 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) · Chroma1-HD model 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 GPT Image 2.5 Sunburst and Chroma1-HD from the same arena and category. Older model versions are not used as substitutes.
More comparisons
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