FLUX.2 Klein 4Bvs.Sana-Sprint 1.6B 1024px

Which one is better?

We have not tested Sana-Sprint 1.6B 1024px ourselves yet. Neither is in the arena. Neither has an API price.

Same task, the first image of each.

FLUX.2 Klein 4B: Typography and layout, first image from the fixed test run — FLUX.2 Klein 4B21 out of 100

Sana-Sprint 1.6B 1024px: Typography and layout, first image from the fixed test run — Sana-Sprint 1.6B 1024pxnot tested yet

Result for “Typography and layout”:only FLUX.2 Klein 4B tested

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.

Missing image run for Sana-Sprint 1.6B 1024px

Three tasks are archived. The infographic was rejected before generation on November 1, 2026 because the ZeroGPU daily quota was exhausted. No overall score is assigned without the fourth output. Run the missing infographic once when the same official demo is available again, then evaluate the complete cohort together.

Documentation

Test protocol of the images

Both models receive the same archived prompt in 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. The images are a practical visual test, not a reconstruction of the arena configuration.

Character and detail

FLUX.2 Klein 4B: fal, requested 1024x1024, n=1, seed=707400387, Fal's published 4B text-to-image endpoint; default four inference steps, estimated cost $0.005000, generated Nov 1, 2026, 9:01 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 4B image SHA 256: 170cebb7cf75bc033a92371199812674f9cfa9641d5e9fb13947ccf892d4ed53

Sana-Sprint 1.6B 1024px image SHA 256: 1d77cacabeb38205299446bc6c5b80f38cf757d98f4251fc44c25340ab870dd9

Product photography

FLUX.2 Klein 4B: fal, requested 1024x1024, n=1, seed=1254275381, Fal's published 4B text-to-image endpoint; default four inference steps, estimated cost $0.005000, generated Nov 1, 2026, 9:00 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 4B image SHA 256: 8fae4a7f6abb7467281c439dc93aa656031626f88c8a54f95f49850cbf045580

Sana-Sprint 1.6B 1024px image SHA 256: 39284e75f1ffa7a286c193927441bca1bee31495f6cf67b4fd024a567a548b09

Typography and layout

FLUX.2 Klein 4B: fal, requested 1024x1024, n=1, seed=1270698692, Fal's published 4B text-to-image endpoint; default four inference steps, estimated cost $0.005000, generated Nov 1, 2026, 9:00 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 4B image SHA 256: 7c2c3e30c20c98e90033087b2b95b151bddc3252dd4aed7092fcbca4ae4ea96e

Sana-Sprint 1.6B 1024px image SHA 256: 5f4459e7adbe7d47fe3ba162ce8e13507b5ea6e3bb4beb5084c862df9ab9e933

The numbers at a glance

Arena ratingfrom votes by users · higher is better

n/a

FLUX.2 Klein 4B

not in the arena

n/a

Sana-Sprint 1.6B 1024px

not in the arena

GraduallyBenchour own rating, 0 to 100 · higher is better

FLUX.2 Klein 4B

Rank 55 of 74

n/a

Sana-Sprint 1.6B 1024px

not tested yet

Price per imagedollars through the API · lower is better

n/a

FLUX.2 Klein 4B

no API price

n/a

Sana-Sprint 1.6B 1024px

no API price

Ranks among the 22 image models with an arena rating and the 74 with a GraduallyBench run; prices compared with 28 models with an API price.

FLUX.2 Klein 4B

Subscription: No Black Forest Labs subscription includes this model. Through other providers from €6.83 a month (Poe Basic, with limited points). 12 plans in Germany.
Via API: No API price known. Access: API, local.
License: Open weights.

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 1, 2026 · Subscription database from Sep 29, 2026 (34 days old)

All data side by side

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

Kennzahl	FLUX.2 Klein 4B	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	37	n/a
GraduallyBench by task
Typography and layoutLegible text, hierarchy, and composition	21	n/a
Product photographyMaterials, reflections, and fine details	54	n/a
Character and detailAnatomy, clothing, and spatial consistency	53	n/a
InfographicNumbers, labels, and visual organization	19	n/a
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	open	open
Access	API, local	local
Parameters	4 billion	1.6 billion
Largest output	not consistently published	not consistently published
Plans in Germanynaming exactly this model	12	n/a

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

Sources: FLUX.2 Klein 4B model 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 4B and Sana-Sprint 1.6B 1024px from the same arena and category. Older model versions are not used as substitutes.

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More matchups

Compare FLUX.2 Klein 4B and Sana-Sprint 1.6B 1024px with other important image models.

View the complete image model comparison

Same prompt, two images

Missing image run for Sana-Sprint 1.6B 1024px

The numbers at a glance

FLUX.2 Klein 4B

Sana-Sprint 1.6B 1024px

All data side by side

Arena ratings by category

No shared arena score in the stored snapshot

Compare another matchup

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