FLUX.2 [klein] 4B
Hugging Face (Black Forest Labs) Open weights
The catch: Only the 4B size is Apache-2.0; FLUX.2 [klein] 9B and FLUX.2 [dev] are under the FLUX Non-Commercial License.
| Access | Open weights |
|---|---|
| Free limits | Free to download and self-host; you pay only for your own compute. 4B-parameter model for text-to-image and multi-reference image editing; the card says it runs on consumer GPUs with about 13GB VRAM. Released 14 Jan 2026. |
| Modality | image |
| Credit card | Not required |
| Commercial use | Allowed |
| Trains on your data | – |
| Licence or terms | Apache-2.0 |
| Context window | – |
| Model id | black-forest-labs/FLUX.2-klein-4B |
| Base URL | – |
| Last checked | 2 Oct 2026 |
How to use FLUX.2 [klein] 4B
Download the weights and serve them yourself; the quickstart below shows one way. Licence: Apache-2.0.
Quickstart
pip install git+https://github.com/huggingface/diffusers.git; Flux2KleinPipeline.from_pretrained("black-forest-labs/FLUX.2-klein-4B", torch_dtype=torch.bfloat16)(prompt=prompt, height=1024, width=1024, guidance_scale=1.0, num_inference_steps=4).images[0]Paste into Claude Code
I want to run the open-weight model "FLUX.2 [klein] 4B" (black-forest-labs/FLUX.2-klein-4B) for my project. Please: 1. Check the model card and tell me the hardware it needs and the simplest way to serve it (vLLM, SGLang, Ollama or a hosted endpoint). 2. Give me a minimal working setup and a test request. 3. Tell me the licence terms for commercial use. 4. If a cheaper or smaller variant would do the job, mention it.
Before you ship on it
- Only the 4B size is Apache-2.0; FLUX.2 [klein] 9B and FLUX.2 [dev] are under the FLUX Non-Commercial License.
- The model card says 'Open weights available for commercial use under the Apache 2.0 license' (huggingface.co/black-forest-labs/FLUX.2-klein-4B).
- Free to run means you pay for the GPUs, the serving stack and the on-call.
Questions
Is FLUX.2 [klein] 4B free?
Yes. Open weights offers it as open weights, with these limits: Self-host free · Apache-2.0. No credit card is needed.
Can I use FLUX.2 [klein] 4B commercially?
Yes, under Apache-2.0. Check the current terms before you ship.
How do I start with FLUX.2 [klein] 4B?
Download the weights and serve them yourself; the quickstart below shows one way. Licence: Apache-2.0.
Source: huggingface.co/black-forest-labs/FLUX.2-klein-4B, checked 2 Oct 2026.