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Black Forest LabsFLUX.2 familyCurrentImage generationReleased 14 Jan 2026

FLUX.2 [klein] (4B / 9B)

Small, fast FLUX.2 models for real-time/local use; 4B is Apache-2.0.

Model idflux-2-klein-4b

Price$0.014 per image

Checked29 September 2026

Where it stands

21newer image generation models since its release

The 5 newest are listed. All image generation models

Before it from Black Forest Labs
FLUX.2 [max]Dec 2025
After it from Black Forest Labs
FLUX 3 Image Klein15 Oct 2026
Weights
Weights are public. Licence: apache-2.0; FLUX Non-Commercial License. See the licence for commercial terms.

How to call it

4 ways to use FLUX.2 [klein] (4B / 9B), with the model id each provider expects.

Providers, model ids, endpoints and docs for FLUX.2 [klein] (4B / 9B)
ProviderModel idEndpointDocs
BFL API flux-2-klein-4b https://api.bfl.ai/v1/flux-2-klein-4b docs.bfl.ai
BFL API flux-2-klein-9b https://api.bfl.ai/v1/flux-2-klein-9b docs.bfl.ai
Hugging Face huggingface.co
Hugging Face huggingface.co

Pricing

Prices for FLUX.2 [klein] (4B / 9B)
Per image$0.014

As published: “per image from (4B; 9B from 0.015; text-to-image and editing)”.

Source: docs.bfl.ai, checked 29 September 2026.

Specs

Input
Text and images
Output
Images
Context window
Not published
Max output
Not published
Open weights
Yes
Licence
apache-2.0 (4B); FLUX Non-Commercial License (9B)
Released
14 January 2026
Status
Current
Type
Image generation

What stands out

What its maker marketed at launch, and what people found later, each with its source.

  • Sub-second generation and editing

    Size-distilled FLUX.2 variants aimed at sub-second inference for both text-to-image and editing.

    Source: docs.bfl.ai

  • Apache-2.0 open weights (4B)

    4B checkpoint is Apache 2.0 - commercially usable open weights; base (undistilled) checkpoints published for fine-tuning/LoRA training.

    Source: huggingface.co

  • KV-cached 9B variant

    Found after launch

    flux-2-klein-9b-preview / FLUX.2-klein-9b-kv (Mar 2026) add KV caching for faster multi-reference editing.

    Source: docs.bfl.ai

Notes

Snapshots flux-2-klein-9b (fixed) and flux-2-klein-9b-preview (latest, KV caching). HF also hosts -base, fp8 and nvfp4 variants. Release date = HF repo creation date.

curl -X POST https://api.bfl.ai/v1/flux-2-klein-4b -H "x-key: $BFL_API_KEY" -H "Content-Type: application/json" -d '{"prompt":"minimal poster, the word KLEIN in bold red"}'

Local: diffusers with black-forest-labs/FLUX.2-klein-4B.

Sources: https://docs.bfl.ai/flux_2/flux2_overview , https://docs.bfl.ai/quick_start/pricing , https://huggingface.co/black-forest-labs