Black Forest Labs · 2026-10-15 · major
FLUX 3 Image Klein — Black Forest Labs' 5.6B open-weights image model
FLUX 3 Image Klein is a 5.6B open-weights model from Black Forest Labs for text-to-image, editing and up to 10 reference images. An INT8 build runs on RTX GPUs with 8GB of VRAM.
A small open-weights FLUX 3 model that makes, edits and combines images on a consumer GPU.
Key specs
| Parameters | 5.6B |
|---|---|
| Min vram (int8) | 8 GB |
Quick facts
| Maker | Black Forest Labs |
|---|---|
| Variants | Base (fine-tuning) + step-distilled |
| License | FLUX Kommunity License |
| Reference images | Up to 10 |
| API price | From $0.009 per 1K image |
| Availability | Hugging Face weights, BFL API, Playground |
Pricing
| BFL API (distilled) · starting price | $0.009 / 1K image |
|---|
What is it?
FLUX 3 Image Klein brings Black Forest Labs' FLUX 3 image line to open weights in a 5.6B-parameter model. One model handles text-to-image, single-image edits and composition from up to 10 reference images, with native 4K output and bounding-box control.
How does it work?
The release has two checkpoints: a Klein Base model for fine-tuning and research, and a step-distilled model that uses 16 steps with no guidance for low-latency generation. A Qwen3-VL-4B-Instruct model works as the text encoder, and the model card warns that short prompts give generic results unless a prompt upsampler is used.
Why does it matter?
Open image models usually trade quality for size. Black Forest Labs claims this one ranks first among open-weights models in its internal tests while fitting on 8GB gaming GPUs, so local and self-hosted image pipelines get a strong default that small companies can use commercially.
Who is it for?
image-pipeline builders, ComfyUI users, fine-tuners
Frequently asked questions
- Can I use FLUX 3 Image Klein commercially?
- FLUX 3 Image Klein ships under the FLUX Kommunity License. Black Forest Labs says it allows free commercial use for individuals and companies with annual revenue under $5M, plus research and non-commercial use. Larger organizations need a self-hosted commercial license or can use the model through the BFL API.
- What GPU do I need to run FLUX 3 Image Klein locally?
- The FLUX 3 Image Klein generator weights take 11.2 GB in BF16 and 5.6 GB in FP8. Black Forest Labs says the INT8 build runs on NVIDIA GeForce RTX GPUs with as little as 8GB of VRAM. With the distilled model in ComfyUI, a 1MP image takes about 4 seconds on an RTX 5090 and under 9 seconds on an RTX 4070.
- How does FLUX 3 Image Klein compare to FLUX.2 klein?
- Black Forest Labs reports that FLUX 3 Image Klein gains 91 Elo in text-to-image and 70 Elo in image editing over FLUX.2 [klein] 9B, while using 38% fewer parameters. In the company's internal evaluations it also rates above the closed Ideogram V4.5 and FLUX.2 [pro].
- Which tools support FLUX 3 Image Klein on day one?
- FLUX 3 Image Klein has day-one support in ComfyUI, Diffusers, TensorRT-LLM, SGLang Diffusion and vLLM-Omni. Black Forest Labs also built FP8, INT8 and NVFP4 versions with NVIDIA, and the weights are on Hugging Face next to a hosted Space and the BFL API.
Try it
https://huggingface.co/black-forest-labs/flux-3-image-klein