FLUX.2 Klein 9B Previewvs.Sana-Sprint 1.6B 1024px
Which one is better?
In our own test, FLUX.2 Klein 9B Preview leads. Neither is in the arena. Neither has an API price.
Test images
Same task, the first image of each. The task with the biggest difference is preselected.
Result for “Infographic”:FLUX.2 Klein 9B Preview 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
FLUX.2 Klein 9B Preview: manual, BFL API /v1/flux-2-klein-9b-preview (distinct preview checkpoint); native 1024x1024, 1:1; one request, first output; seed=3453819885; output_format=png; no reference images or negative prompt, generated Nov 2, 2026, 7:05 PM. Source
Sana-Sprint 1.6B 1024px: manual, 1:1, one request, first output, one image, provider-side randomize seed enabled, observed seed 889651570, native 1024x1024, 2 inference steps, guidance 4.5, no prompt enhancement, no reference images, exact checkpoint Efficient-Large-Model/Sana_Sprint_1.6B_1024px_diffusers, Space commit b42328123ed688df4bee46e52c60cc1dc62c045a, generated Nov 1, 2026, 9:42 PM. Source
Protocol gradually-image-comparison-v1. Prompt SHA 256: 985a75b38642a9f0e5e0c0e0c67f1b7f67780d42bd2168fa24e9a7a7a94b0da6
FLUX.2 Klein 9B Preview image SHA 256: 83bd206858a0d2bfab8a9d3bb7d90de6ff568017464a8168726175a6b324a90c
Sana-Sprint 1.6B 1024px image SHA 256: 1d77cacabeb38205299446bc6c5b80f38cf757d98f4251fc44c25340ab870dd9
Infographic
FLUX.2 Klein 9B Preview: manual, BFL API /v1/flux-2-klein-9b-preview (distinct preview checkpoint); native 1024x1024, 1:1; one request, first output; seed=1679342581; output_format=png; no reference images or negative prompt, generated Nov 2, 2026, 7:06 PM. Source
Sana-Sprint 1.6B 1024px: manual, 1:1, one request, first output, one image, provider-side randomize seed enabled, observed seed 853526908, native 1024x1024, 2 inference steps, guidance 4.5, no prompt enhancement, no reference images, exact checkpoint Efficient-Large-Model/Sana_Sprint_1.6B_1024px_diffusers, Space commit b42328123ed688df4bee46e52c60cc1dc62c045a; an earlier request on 2026-11-01 was rejected before generation by the ZeroGPU quota, generated Nov 2, 2026, 2:30 PM. Source
Protocol gradually-image-comparison-v1. Prompt SHA 256: ed65cb4e6a51e2336f8b149ad4cbb16e020f07d527ad94362e719d2dcf91d94f
FLUX.2 Klein 9B Preview image SHA 256: deb8da580546e3d22e20222c5c7e8c1a95197f27be4bff0b064eba603bda7b47
Sana-Sprint 1.6B 1024px image SHA 256: da4ed66ab2f25ea33c81978bc687142d50f7f7d01db096169151e70f1648ec43
Product photography
FLUX.2 Klein 9B Preview: manual, BFL API /v1/flux-2-klein-9b-preview (distinct preview checkpoint); native 1024x1024, 1:1; one request, first output; seed=132780547; output_format=png; no reference images or negative prompt; first provider output recovered by GET after local regional API validation stopped polling; no regeneration, generated Nov 2, 2026, 7:04 PM. Source
Sana-Sprint 1.6B 1024px: manual, 1:1, one request, first output, one image, provider-side randomize seed enabled, observed seed 178858232, native 1024x1024, 2 inference steps, guidance 4.5, no prompt enhancement, no reference images, exact checkpoint Efficient-Large-Model/Sana_Sprint_1.6B_1024px_diffusers, Space commit b42328123ed688df4bee46e52c60cc1dc62c045a, generated Nov 1, 2026, 9:42 PM. Source
Protocol gradually-image-comparison-v1. Prompt SHA 256: c67fd71e91304458a2feef5c91efa8677260fab0c0099a29a2c52cb579f5b2f3
FLUX.2 Klein 9B Preview image SHA 256: b1f17cd46fcd8f8b862da7c59900c1616ac3db8052d92a344720b7dc7fcb75ea
Sana-Sprint 1.6B 1024px image SHA 256: 39284e75f1ffa7a286c193927441bca1bee31495f6cf67b4fd024a567a548b09
Typography and layout
FLUX.2 Klein 9B Preview: manual, BFL API /v1/flux-2-klein-9b-preview (distinct preview checkpoint); native 1024x1024, 1:1; one request per attempt; two submissions; original signed output expired after local retrieval failure; first output of technical repeat with unchanged prompt and seed; seed=4230828387; output_format=png; no reference images or negative prompt, generated Nov 2, 2026, 7:06 PM. Source
Sana-Sprint 1.6B 1024px: manual, 1:1, one request, first output, one image, provider-side randomize seed enabled, observed seed 37807657, native 1024x1024, 2 inference steps, guidance 4.5, no prompt enhancement, no reference images, exact checkpoint Efficient-Large-Model/Sana_Sprint_1.6B_1024px_diffusers, Space commit b42328123ed688df4bee46e52c60cc1dc62c045a, generated Nov 1, 2026, 9:42 PM. Source
Protocol gradually-image-comparison-v1. Prompt SHA 256: 2e012c3d14ee5dd02203a94f394ca80a5038cdebd6032b25a8b8a221f2255419
FLUX.2 Klein 9B Preview image SHA 256: 6cc5a70118def87bf0ec737b20c9dd56c3a7dd3ec776e007b8a5fdadd4c27849
Sana-Sprint 1.6B 1024px image SHA 256: 5f4459e7adbe7d47fe3ba162ce8e13507b5ea6e3bb4beb5084c862df9ab9e933
The numbers at a glance
FLUX.2 Klein 9B Preview
not in the arena
Sana-Sprint 1.6B 1024px
not in the arena
FLUX.2 Klein 9B Preview
Rank 48 of 108
Sana-Sprint 1.6B 1024px
Rank 96 of 108
FLUX.2 Klein 9B Preview
no API price
Sana-Sprint 1.6B 1024px
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.
FLUX.2 Klein 9B Preview
- Subscription
- n/a No plan in Germany names exactly this model.
- Via API
- No API price known. Access: API.
- Weights
- unknown.
Sana-Sprint 1.6B 1024px
- 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.
GraduallyBench from Nov 3, 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 | FLUX.2 Klein 9B Preview | Sana-Sprint 1.6B 1024px |
|---|---|---|
| Ratings | ||
| Arena ratingfrom votes by users, higher is better | n/a | n/a |
| Arena rank | n/a | n/a |
| Arena votesmore votes, a safer rating | n/a | n/a |
| GraduallyBenchour own rating, 0 to 100 | 62 | 21 |
| GraduallyBench by task | ||
| Typography and layoutLegible text, hierarchy, and composition | 56 | 21 |
| Product photographyMaterials, reflections, and fine details | 73 | 27 |
| Character and detailAnatomy, clothing, and spatial consistency | 45 | 26 |
| InfographicNumbers, labels, and visual organization | 75 | 10 |
| API price | ||
| Per imagelower is better | n/a | n/a |
| 100 images | n/a | n/a |
| Profile | ||
| Released | n/a | Mar 22, 2025 |
| Weightsopen means: runs locally | unknown | open |
| Lifecycle | Preview API route with newer quality/speed improvements; the stable 9B route remains separate | no notice |
| Access | API | local |
| Parameters | 9 billion | 1.6 billion |
| Largest output | not consistently published | not consistently published |
| Plans in Germanynaming exactly this model | n/a | n/a |
API prices for one image at 1,024 × 1,024 pixels according to Artificial Analysis.
Sources: FLUX.2 Klein 9B Preview model source, status source (verified Nov 1, 2026) · Sana-Sprint 1.6B 1024px 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 FLUX.2 Klein 9B Preview and Sana-Sprint 1.6B 1024px from the same arena and category. Older model versions are not used as substitutes.
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