Overview
- Tool name: FLUX 3 Image (including FLUX 3 Image Klein)
- Developer: Black Forest Labs (Germany, founded by the original Stable Diffusion team)
- Official website: https://bfl.ai
- Category: AI image models
- License: FLUX Kommunity License (open weights)
FLUX 3 is Black Forest Labs' 2026 image model family. FLUX 3 Image Klein shipped as open weights on October 15, 2026 - the family's second open release (the first was FLUX 3 Action, a robot-control model).
Core capabilities:
- One set of weights, three jobs: text-to-image, single-reference editing, and multi-reference composition from up to 10 reference images
- Native 4K output with pixel-perfect editing (unedited regions preserved exactly)
- Bounding-box control: specify where an element goes, or confine an edit to one region - a requirement for product-imagery workflows
- Very low bar to run: 5.6B parameters; the INT8 build runs on GeForce RTX cards with 8GB of VRAM via ComfyUI or Diffusers (BF16 weights 11.2GB, FP8 5.6GB)
- Two checkpoints: Base (50 steps, for fine-tuning and LoRA training) and distilled (16 steps, what the BFL API serves)
API pricing (official, per image)
- FLUX 3 Image Klein: 768 squared $0.008 / 1K $0.009 / 1.5K $0.011 / 2K $0.014 / 4K $0.036 (text-to-image and editing priced alike)
- FLUX 3 Image (full): 768 squared $0.041 / 1K $0.048 / 1.5K $0.07 / 2K $0.10 / 4K $0.607
- Reference images and prompts are free; rejected, failed or withheld generations are not charged
Pricing verified against blackforestlabs.ai and the bfl.ai launch announcement (October 2026).
Ecosystem
Day-one support in ComfyUI, Hugging Face Diffusers, TensorRT-LLM, SGLang Diffusion and vLLM-Omni; LoRA training via Ostris' AI Toolkit with recipes in NVIDIA NeMo AutoModel. Trained on NVIDIA GB200 NVL72, and on GB300 the NVFP4 distilled build produces a 1MP image in under 0.6 seconds.
License notes
FLUX Kommunity License: free commercial use for individuals and companies under $5M annual revenue, plus research and non-commercial use; larger organizations deploy via the BFL API or self-hosted licensing. Note the model card states this is "not blanket permission for commercial fine-tuning or distribution."
Who it is for
- Local / private image production: runs on an 8GB consumer card, data never leaves your machine
- Product and e-commerce imagery: 10 references, bounding boxes, pixel-exact preservation of unedited areas
- High-throughput low-cost generation: Klein at $9 per thousand 1K images
- Brand customization: the Base checkpoint supports LoRA fine-tuning
Limitations
- All ranking and Elo claims are internal evaluations; no independent third-party benchmark yet
- The $5M revenue threshold means mid-size and large enterprises must use the API or a license
- Requires a prompt upsampler (or another LLM) to write the full captions the model expects
Frequently asked questions
Is FLUX 3 Image Klein free for commercial use?
Under the FLUX Kommunity License, individuals and companies under $5M annual revenue can use it commercially at no charge; above that, use the API or self-hosted licensing.
What does it cost?
The BFL API bills per image: Klein at $0.009 per 1K image and $0.036 at 4K; the full FLUX 3 Image at $0.048 per 1K image.
Will it run on 8GB of VRAM?
Yes - the INT8 build runs on GeForce RTX cards with as little as 8GB VRAM through ComfyUI or Diffusers (per BFL).
FLUX 3 vs Stable Diffusion 4 vs Nano Banana?
FLUX 3 for single-card private deployment and precise layout control; SD4 Ultra for native 4096-squared output and its text-rendering module; Nano Banana 2 for the Google ecosystem and lowest per-image cost.
*This page is not affiliated with Black Forest Labs. Pricing and specs verified as of October 2026 (bfl.ai announcement and pricing page); confirm current figures on the official site.*