# FLUX 3 Image Klein

> Updated 2026-10-16 · https://imageklein.com/

FLUX 3 Image Klein is a 5.6-billion-parameter open-weights image model from Black Forest Labs, released on October 15, 2026. One model does text-to-image, image editing and multi-reference generation with up to 10 reference images, at up to native 4K, with bounding boxes to control where things go — and its INT8 build runs on NVIDIA GeForce RTX GPUs with as little as 8 GB of VRAM.

The launch video · Black Forest Labs on X, October 15, 2026
[Launch post and video on X](https://x.com/bfl_ai/status/2110751201105256925)

**5.6B**parameters
**4K**native output
**10**reference images
**8 GB**min. VRAM (INT8)
**$0.009**per 1K image (API)

Capabilities

## One small model. Generate, edit and compose.

*{ICON_SPARK}*Text-to-imagePhotoreal, illustration, anime, typography — with legible text inside the image, up to native 4K.
*{ICON_WAND}*Pixel-perfect editingChange one thing with an instruction. Through the API, untouched pixels stay exactly the same.
*{ICON_LAYERS}*Up to 10 referencesCombine people, products, styles and places from up to 10 images into one new picture.
*{ICON_BOX}*Bounding boxesSay exactly where things go on a 0–1000 grid: place, move, recolor or remove elements. [Format →](https://imageklein.com/flux-3-image-klein-bounding-boxes)
*{ICON_CHIP}*Runs on your GPUINT8 build on 8 GB GeForce RTX cards; ≈4 s per image on an RTX 5090. [Setup →](https://imageklein.com/run-flux-3-image-klein-locally)
*{ICON_SHIELD}*Free commercial useFLUX Kommunity License: free for individuals and companies under $5M revenue. [License →](https://imageklein.com/flux-3-image-klein-license)

At a glance

## FLUX 3 Image Klein specs

Everything Black Forest Labs has published so far, in one table. Benchmarks are BFL's own.
[Read the full explainer →](https://imageklein.com/what-is-flux-3-image-klein)

| Made by | Black Forest Labs (BFL), Freiburg, Germany and San Francisco |
|---|---|
| Released | October 15, 2026 (open weights) |
| Size | 5.6B-parameter image generator; text encoder Qwen3-VL-4B-Instruct (separate) |
| Does | Text-to-image, image editing, multi-reference generation (up to 10 reference images) |
| Output | Up to native 4K; text rendering in images |
| Control | Bounding boxes on a 0–1000 grid to place, move, recolor, replace or remove elements |
| Checkpoints | Klein (step-distilled, 16 steps, no guidance) and Klein Base (50 steps, guidance 3.5, for fine-tuning); FP8, NVFP4 and INT8 builds |
| Weights size | 11.2 GB in BF16, 5.6 GB in FP8 (generator only) |
| Minimum GPU | NVIDIA GeForce RTX with 8 GB VRAM (INT8 build, ComfyUI or Diffusers) |
| Speed | ≈4 s per 1 MP image on RTX 5090, under 9 s on RTX 4070 (distilled + INT8, BFL/NVIDIA figures) |
| API | Model id flux-3-image-klein, from $0.009 per 1K image |
| License | FLUX Kommunity License — free commercial use under $5M annual revenue |
| Runs in | ComfyUI, Hugging Face Diffusers, TensorRT-LLM, SGLang Diffusion, vLLM-Omni; LoRA training in Ostris AI Toolkit and NVIDIA NeMo AutoModel |

Price

## Five times cheaper than FLUX 3 Image

FLUX 3 Image Klein**$0.009**per 1K image · $0.036 at 4K
FLUX 3 Image**$0.048**per 1K image · $0.607 at 4K
Nano Banana 2.1**$0.034**per 1K image · $0.113 at 4K
FLUX.2 [klein] 9B**$0.015**per image

API list prices on October 15, 2026. [All resolutions and sources →](https://imageklein.com/flux-3-image-klein-api-pricing)

What's new

## vs FLUX.2 [klein]: +91 Elo, 38% fewer parameters

FLUX 3 Image Klein keeps the big FLUX 3 Image model's native 4K output, bounding boxes and pixel-precise editing, and adds up to 10 reference images. In BFL's own blind evaluations it scores **+91 Elo in text-to-image and +70 Elo in image editing over FLUX.2 [klein] 9B**. [Full comparison →](https://imageklein.com/flux-3-image-klein-vs-flux-2-klein)

Guides

## Start using FLUX 3 Image Klein

[**Try the free demo**Official Hugging Face Space — text-to-image, edits, bounding boxes.huggingface.co ↗](https://huggingface.co/spaces/black-forest-labs/flux-3-image-klein)
[**Run it locally**ComfyUI or Diffusers, copy-paste code, VRAM and speed tables.Guide →](https://imageklein.com/run-flux-3-image-klein-locally)
[**API pricing**Model id flux-3-image-klein, $0.008–$0.036 per image.Guide →](https://imageklein.com/flux-3-image-klein-api-pricing)
[**License**The $5M rule, what's allowed and what isn't.Guide →](https://imageklein.com/flux-3-image-klein-license)
[**Prompting guide**Long prompts, references, text in images, edits.Guide →](https://imageklein.com/flux-3-image-klein-prompting)
[**Bounding boxes**The JSON format with ready-to-copy examples.Guide →](https://imageklein.com/flux-3-image-klein-bounding-boxes)

## FAQ

**What is FLUX 3 Image Klein?**
FLUX 3 Image Klein is a 5.6-billion-parameter open-weights image model from Black Forest Labs, released on October 15, 2026. One model does text-to-image, image editing and multi-reference generation with up to 10 reference images, at up to native 4K, with bounding boxes to control where things go — and its INT8 build runs on NVIDIA GeForce RTX GPUs with as little as 8 GB of VRAM.

**Is FLUX 3 Image Klein free?**
The weights are free to download from Hugging Face (after accepting the license) and free to use for research, non-commercial work, and commercial work by individuals and companies with under $5 million in annual revenue (FLUX Kommunity License). Larger companies need a self-hosting license from Black Forest Labs or can use the paid API. There is also a free demo on Hugging Face Spaces.

**How much VRAM does FLUX 3 Image Klein need?**
Black Forest Labs says the INT8 build runs on NVIDIA GeForce RTX GPUs with as little as 8 GB of VRAM through ComfyUI or Diffusers. The full BF16 reference code is much heavier: the model card measures about 31 GB peak (25–26 GB for NVFP4/FP8) on a data-center GPU at 1024×1024.

**How fast is FLUX 3 Image Klein?**
With the distilled model and the INT8 build in ComfyUI, a 1-megapixel image takes about 4 seconds on an RTX 5090 and under 9 seconds on an RTX 4070 (NVIDIA measurements published by BFL). Through the BFL API, median end-to-end latency at 1 MP is 4.54 s for text-to-image and 7.18 s for editing.

**How much does the FLUX 3 Image Klein API cost?**
Per image, the same for generation and editing: $0.008 at 768×768, $0.009 at 1K, $0.011 at 1.5K, $0.014 at 2K and $0.036 at 4K (as reported by VentureBeat from BFL's pricing).

**Can I use FLUX 3 Image Klein commercially?**
Yes if you are an individual or a company with less than US$5 million in gross annualized revenue (including affiliates), under the FLUX Kommunity License. Above that, use the BFL API or buy a self-hosting license.

**Where can I download FLUX 3 Image Klein?**
From Hugging Face: black-forest-labs/flux-3-image-klein (distilled, includes FP8/NVFP4 builds, the text encoder and autoencoder) and black-forest-labs/flux-3-image-klein-base (for fine-tuning). Reference code is on GitHub at black-forest-labs/flux-3-image-klein; a ComfyUI-packaged repo is black-forest-labs/flux-3-image-klein-comfy.


## Sources

- [Black Forest Labs on X — launch post (Oct 15, 2026)](https://x.com/bfl_ai/status/2110751201105256925)
- [Black Forest Labs — FLUX 3 Image Klein (blog, Oct 15, 2026)](https://bfl.ai/blog/flux-3-image-klein)
- [Hugging Face — black-forest-labs/flux-3-image-klein (model card)](https://huggingface.co/black-forest-labs/flux-3-image-klein)
- [Hugging Face Space — FLUX 3 Image Klein demo](https://huggingface.co/spaces/black-forest-labs/flux-3-image-klein)
- [Press release via GlobeNewswire (Oct 15, 2026)](https://www.globenewswire.com/news-release/2026/10/15/3381905/0/en/black-forest-labs-expands-access-to-frontier-visual-intelligence-with-open-weights-release-of-flux-3-image-klein.html)
- [VentureBeat — FLUX 3 Image Klein weights, free commercial use for smaller businesses](https://venturebeat.com/technology/black-forest-labs-opens-flux-3-image-klein-weights-with-free-commercial-use-limited-to-smaller-businesses)