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Flux.2 Klein 4B API

Text to Image

Smallest and fastest Flux.2 model for rapid image generation at $0.0098/MP.

Click or drag & dropPNG, JPG, WEBP, GIF · Max 100MB
Output

Your generated image will appear here

Features

What Flux.2 Klein 4B API offers

Smallest Flux.2 Klein stack at roughly 4B parameters for the lowest latency in the family
Same API surface as Klein 9B: prompt, aspect_ratio, resolution, optional seed, optional references
Resolution presets: 0.6 MP, 1 MP, 2 MP, or 4 MP
Wide range of aspect ratios including 21:9
Up to 10 reference images per call in the playground
No Flex-style steps or CFG controls (by design)
Generate and poll JSON endpoints like other image models

Use cases

Built for

Primary

Real-time previews - Fastest turnaround when layout matters more than maximum detail

#2

Cost-sensitive batches - Many assets per hour when pricing favors the smallest Klein tier

#3

A/B prompt tests - Cheap iterations before re-running winners on 9B or full Flux.2

#4

Thumbnail grids - Low megapixel settings for grids and contact sheets

#5

Automated pipelines - Slots where model size and cost matter more than marginal quality gains

FAQ

About Flux.2 Klein 4B API

It is the smallest Flux.2 Klein variant on Unifically, focused on speed. You pass the same parameters as Klein 9B: prompt, resolution, aspect ratio, optional seed, and optional reference URLs.

Klein 4B trades model capacity for shorter runtime. Expect comparable controls but slightly less headroom on fine detail versus Klein 9B, especially at higher megapixel outputs.

The playground matches Klein 9B: prompt, aspect_ratio, resolution, optional seed, and reference images. It does not add Flux.2 Flex controls such as steps or CFG.

Billing uses the black-forest-labs/flux.2-klein-4b key. Check live rates in the Unifically console because they change independently of Klein 9B.