Is FLUX 2 Open Source? Licenses and Local Use
FLUX 2 licensing depends on the model: Apache-2.0 klein 4B, noncommercial dev weights, or hosted Pro. Check download options, output rights, and local use.
FLUX 2 is partly open source. As of October 2026, Black Forest Labs offers FLUX.2 [klein] 4B and Base 4B weights under Apache-2.0, which permits commercial use under its terms. FLUX.2 [dev] has downloadable weights with noncommercial restrictions. BFL offers [pro], [flex], and [max] as hosted models and lists no public weight downloads for them. The hosted FLUX.2 Pro generator on flux-3image, an independent third-party app, provides browser access to Pro.
Which FLUX.2 weights can you download and use commercially?
BFL's FLUX.2 inference repository lists the licenses for downloadable checkpoints. Here are the 4B options, dev, and hosted models covered below:
| Model | Downloadable weights? | License or access |
|---|---|---|
| FLUX.2 [klein] 4B | Yes | Apache-2.0; commercial use permitted under its terms |
| FLUX.2 [klein] Base 4B | Yes | Apache-2.0; undistilled version suited to fine-tuning |
| FLUX.2 [dev] | Yes | FLUX Non-Commercial License; commercial model use requires a separate license |
| FLUX.2 [pro], [flex], [max] | No public download listed | Hosted generation and editing |
BFL's model overview confirms the Base 4B license and hosted options. Choose klein 4B for generation or Base 4B for fine-tuning. A download labeled FLUX.2 does not tell you its license: check the exact checkpoint.
The inference code uses Apache-2.0. That code license does not change the license of the weights it loads. For klein 4B and Base 4B, the Apache license permits use and modification under its terms. Redistribution requires a license copy, retained notices, and notices identifying modified files.
Can you sell images made with FLUX.2 dev?
The dev license separates running the model from using its outputs. Section 2(d) permits commercial use of generated images, subject to restrictions, including a ban on using them to train, fine-tune, or distill a competing model.
The model itself is licensed for noncommercial use, with non-production limits in the license's definition of permitted uses. Section 2(b) requires a separate license for commercial model use. Permission to sell an image therefore does not authorize operating a commercial image-generation service with dev weights.
What do you need to run klein 4B locally?
The klein 4B model card links the downloadable files and installation instructions. Its Diffusers example uses Flux2KleinPipeline, loads black-forest-labs/FLUX.2-klein-4B in torch.bfloat16, and enables CPU offload to reduce GPU memory use. It generates a 1024 × 1024 image in four inference steps.
BFL's memory estimates conflict: the inference repository says roughly 8 GB of VRAM for klein 4B, while the model card says roughly 13 GB. Check the guidance for your runtime, precision, and offload settings before downloading. Local inference was not run for the example below, so no measured memory requirement is available here.
How does hosted Pro access differ from downloading weights?
The FLUX.2 model pages provide browser generation and editing. On this site, Pro supports 1K or 2K output and up to eight references. You receive image files; the service does not provide Pro weights for local use or fine-tuning.
The existing Pro product-page example starts with an unbranded white sneaker. Its published prompt description specifies white leather, a gum sole, a gray studio background, a soft shadow, and a three-quarter view. The edit description asks for a mossy rock beside a stream in morning mist while preserving the shoe's shape, leather, sole, and laces. These are descriptions from the product page; the exact submitted prompts are unavailable.
Published hosted Pro example: FLUX.2 [pro], 1K, 1:1 (1024 × 1024). This studio image serves as the edit reference.
Published hosted Pro edit: FLUX.2 [pro], 1K, 4:3 (1024 × 768), using the studio image as one reference.
The edit preserves the white upper and gum sole, but the leather grain is visibly coarser. This pair demonstrates hosted Pro editing only; it cannot establish the quality or hardware needs of local klein.
As of October 2026, the pricing page lists Pro at 3 credits for 1K, plus 3 per reference. A one-reference 1K edit costs 6 credits at those rates. It also lists free klein generation at 1K and editing with one uploaded photo. Browser access does not include model weights.
The FLUX 3 vs FLUX 2 examples compare hosted FLUX 3 Image and FLUX.2 [max] with the same prompts. For local FLUX.2 use, start with a downloadable checkpoint and its own license and setup instructions.