ImageKleinStart creatingWho can use it for free?
| You are… | Self-host the weights | BFL API |
|---|---|---|
| Researcher, hobbyist, non-commercial | Free | Paid per image |
| Individual or company under $5M revenue | Free, including commercial output | Paid per image |
| Company at or above $5M revenue | Needs a commercial self-hosting license | Allowed, paid per image |
The revenue test counts affiliates. BFL hasn't published a standard price for self-hosting licenses — contact BFL.
What the license forbids
- Military use and surveillance, including related R&D; biometric processing.
- Unlawful, fraudulent, defamatory or abusive use; CSAM and non-consensual intimate images.
- Violating third-party rights, including publicity and digital-replica rights (don't fake real people).
- Using the model, its derivatives or its outputs to improve another AI model with a similar function.
- Breaking export controls and sanctions.
The commercial exception covers generating outputs; it is not blanket permission to commercially distribute fine-tuned weights. The “FLUX” and “Black Forest Labs” names need BFL's written permission beyond descriptive references.
Other parts
The text encoder, Qwen3-VL-4B-Instruct, is Apache-2.0. Earlier, FLUX.2 [klein] 4B was Apache-2.0 and FLUX.2 [klein] 9B was non-commercial only — FLUX 3 Image Klein sits in between.
This is a plain-English summary, not legal advice. The license text on the Hugging Face repo is what applies.