---
license: apache-2.0
base_model: black-forest-labs/FLUX.2-klein-4B
tags:
  - text-to-image
  - safetensors
  - mflux
  - mlx
  - flux2
  - flux2-klein
  - quantized
  - 4bit
  - apple-silicon
library_name: mflux
pipeline_tag: text-to-image
---

# FLUX.2 [klein] 4B — mflux 4-bit quantized

4-bit quantized weights of [FLUX.2 [klein] 4B](https://huggingface.co/black-forest-labs/FLUX.2-klein-4B) by Black Forest Labs, optimized for [mflux](https://github.com/filipstrand/mflux) on Apple Silicon.

| | Full precision | This repo (4-bit) |
|---|---|---|
| **Size** | ~8 GB | **4.3 GB** |
| **Framework** | diffusers / mflux | mflux only |
| **Hardware** | CUDA / MLX | Apple Silicon (MLX) |

## Quickstart

### Install mflux

```bash
pip install mflux
```

### Generate an image

```bash
mflux-generate-flux2 \
  --model RunPod/FLUX.2-klein-4B-mflux-4bit \
  --prompt "A cute robot standing in a field of flowers, digital art" \
  --width 1024 \
  --height 1024 \
  --steps 4 \
  --seed 42 \
  --output output.png
```

### Python usage

```python
from mflux import Flux2

flux = Flux2(
    model="RunPod/FLUX.2-klein-4B-mflux-4bit",
    base_model="flux2-klein-4b",
)

image = flux.generate_image(
    prompt="A cute robot standing in a field of flowers, digital art",
    width=1024,
    height=1024,
    num_inference_steps=4,
    seed=42,
)

image.save("output.png")
```

## Details

- **Base model**: [black-forest-labs/FLUX.2-klein-4B](https://huggingface.co/black-forest-labs/FLUX.2-klein-4B) (Apache 2.0)
- **Quantization**: 4-bit via MLX `nn.quantize` (group_size=64), created with `mflux-save --quantize 4`
- **Requirements**: [mflux](https://github.com/filipstrand/mflux) v0.16.0+, Apple Silicon Mac
- **Performance**: ~11s for 512x512 (4 steps) on M3 Pro 18GB

## How this was created

```bash
pip install mflux
mflux-save \
  --path ./FLUX.2-klein-4B-mflux-4bit \
  --model flux2-klein-4b \
  --quantize 4
```

## About FLUX.2 [klein]

FLUX.2 [klein] 4B is a 4 billion parameter rectified flow transformer by [Black Forest Labs](https://bfl.ai) for fast image generation and editing. It delivers state-of-the-art quality with sub-second inference on consumer hardware.

- Ultra-fast inference (4 steps)
- Text-to-image and multi-reference image editing
- Apache 2.0 — fully open for commercial use
- [Blog post](https://bfl.ai/blog/flux2-klein-towards-interactive-visual-intelligence) | [GitHub](https://github.com/black-forest-labs/flux2)

## License

Apache 2.0, inherited from the [original model](https://huggingface.co/black-forest-labs/FLUX.2-klein-4B).

## Credits

- **Model**: [Black Forest Labs](https://blackforestlabs.ai)
- **mflux**: [Filip Strand](https://github.com/filipstrand/mflux)
- **Quantization & upload**: [Runpod](https://runpod.io) / [OpenClaw2Go](https://github.com/runpod-workers/openclaw2go)