FLUX Kommunity License v1.0 Summary
FLUX 3 Klein (full name FLUX 3 Image Klein) is an open-weight model made by Black Forest Labs (BFL), a German company that makes the FLUX model family. The model weights are released under the FLUX Kommunity License v1.0.
According to the summary on the Hugging Face model card, the license sets rules based on how you use the model and your annual revenue. Non-commercial use is allowed. In addition, individuals and companies with an annual revenue under US$5 million may run the model in production and use the generated images commercially. However, the model card states that this permission does not by itself allow commercial fine-tuning or redistribution of the model.
| Use Case or Action | Status under Model Card Summary |
|---|---|
| Non-commercial use | Allowed |
| Running the model in production (annual revenue under US$5 million) | Allowed |
| Commercial use of generated images (annual revenue under US$5 million) | Allowed |
| Commercial fine-tuning of the model | Not covered by the permission above; read the full license |
| Redistributing the model | Not covered by the permission above; read the full license |
If you plan to run the weights on your own machine, see our guide on downloading the weights and check the VRAM and hardware requirements.
You Must Read the Full License Text Yourself
The weights for FLUX 3 Klein are open, but they are gated on Hugging Face. You must log in to a Hugging Face account and accept the license agreement before you can access the files.
Because the full LICENSE.md file requires a login to view, we have not read or reviewed the complete legal text. The points on this page come only from the public summary on the model card as of October 16, 2026. Before you download the weights, deploy the model in a business, or sell output, you must log in to the FLUX 3 Image Klein repository and read the full LICENSE.md file yourself.
Open-Weight License vs. API Terms
There are two ways to run FLUX 3 Klein: by downloading the open weights to run locally (such as in a ComfyUI setup), or by generating images through a hosted service.
It is our understanding that using Black Forest Labs’ API is governed by BFL’s API terms, not by the FLUX Kommunity License v1.0 that covers the downloadable weights. We have not reviewed BFL’s API terms in detail. If you connect to the endpoints described in the BFL documentation, you should review the terms associated with your BFL API account. You can read more about how the endpoints work on our API guide.
Klein Studio (flux3klein.org) is an unofficial website and is not affiliated with or endorsed by Black Forest Labs. Our site runs FLUX 3 Klein through Black Forest Labs’ API, where visitors can try the generator for free (3 images a day at 1K resolution with no sign-up). When using our tool, please also follow our acceptable use policy.
Trademark Rules
The model card includes specific rules about naming and branding. Using the Black Forest Labs (BFL) and FLUX trademarks requires prior written permission from the company. The only exception is for necessary attribution and descriptive references, provided that your use does not imply endorsement by Black Forest Labs.
Not Legal Advice
Nothing on this page is legal advice. Klein Studio is an independent, unofficial resource providing a plain-language look at public documentation checked on October 16, 2026. If you have questions about whether your company meets the US$5 million revenue threshold, or if you want to fine-tune or redistribute the model commercially, consult a qualified lawyer and read the license files from Black Forest Labs yourself.