The Pulse
Black Forest Labs Releases 5.6B-Parameter FLUX 3 Image Klein
Black Forest Labs released FLUX 3 Image Klein, a 5.6-billion-parameter open-weights model for image generation, editing and multi-reference work. The model comes with base and distilled versions, local GPU options and a license that limits
AI.info Team · Written with AI ·
Black Forest Labs released FLUX 3 Image Klein on October 15, 2026, offering a 5.6-billion-parameter model for image generation, editing and work guided by as many as 10 reference images. The company says the open-weights release brings capabilities from its larger FLUX 3 Image model, including native 4K generation, pixel-level editing and bounding-box controls for placing elements or limiting edits.
Two checkpoints, three compact formats
The release includes a base checkpoint intended for fine-tuning and a step-distilled version aimed at lower-latency generation. Black Forest Labs also published FP8, INT8 and NVFP4 builds developed with NVIDIA support. Its post says the INT8 version can run on NVIDIA GeForce RTX cards with as little as 8GB of video memory through ComfyUI or Diffusers.
For local generation, Black Forest Labs reports that the distilled INT8 model produces a 1-megapixel image in about four seconds on an RTX 5090 and in under nine seconds on an RTX 4070 using ComfyUI. Those are the company’s reported results for a particular model build and setup, not a universal timing for every workflow. The company lists generator weights at 11.2GB in BF16 and 5.6GB in FP8.
Black Forest Labs’ benchmark claims
Black Forest Labs says its internal evaluations put Klein first among the models it tested for text-to-image generation, multi-reference generation and image editing. Its comparison includes the closed models Ideogram V4.5 and FLUX.2 [pro], and larger open-weights models including Qwen-Image 2.1 at 7 billion parameters and Krea 2 at 12.9 billion. The company counts image-generator parameters but not text encoders; Krea 2 does not support image editing and is excluded from that comparison.
Against the company’s earlier FLUX.2 [klein] 9B, Black Forest Labs reports a 91-point Elo gain in text-to-image and a 70-point gain in image editing, with 38% fewer parameters. Those results come from the company’s own evaluations, rather than an independently published benchmark. The post also reports end-to-end API latency of 4.54 seconds for text-to-image and 7.18 seconds for editing at 1 megapixel, while noting that the compared services were timed differently: Klein on BFL servers and other models from the client.
Commercial use depends on company size
Users can download the base and distilled weights from Hugging Face, use the model through Black Forest Labs’ API, or try it in the company’s playground. The release has day-one support in ComfyUI and Hugging Face Diffusers, among other listed inference tools, and includes support for LoRA training through Ostris’s AI Toolkit and NVIDIA NeMo AutoModel recipes. API pricing starts at $0.009 for a 1K image, according to the release.
The weights use Black Forest Labs’ FLUX Kommunity License, not a license that grants unrestricted commercial use to every organization. The company says individuals and businesses with annual revenue below $5 million may use the model commercially for free; larger organizations need its self-hosted licensing options or API. Klein is the second open-weights release in the FLUX 3 family, after FLUX 3 Action, which Black Forest Labs released for robot control.