# FLUX.2 Klein: A Compact 4B Open-Source Image Model

> The new 4-billion-parameter model from Black Forest Labs offers an efficient, transformer-based alternative to latent diffusion for image generation.

Published by The Open Weights on Jan 14, 2026. Canonical: https://theopenweights.com/news/flux-2-klein-4b-rwg5

## Key facts

- Company: Black Forest Labs
- Model: FLUX.2 Klein 9B
- Version: FLUX.2 klein
- Category: Text → Image
- Modalities: Image Editing, Text → Image
- License: Apache 2.0 (Open weights, commercial use allowed)
- Parameters: 4B
- Architecture: Flux2KleinPipeline
- Precision: BF16
- Weights size: 7.8 GB
- Resolution: 1024×1024
- Significance: notable
- Published: 2026-01-14
- Last verified: 2026-06-17
- Hugging Face: https://huggingface.co/black-forest-labs/FLUX.2-klein-base-4B
- Canonical URL: https://theopenweights.com/news/flux-2-klein-4b-rwg5

Black Forest Labs has released FLUX.2 klein, a new 4-billion-parameter open-source model for text-to-image generation and editing. Released under a permissive Apache 2.0 license, the model provides a new, highly efficient option for developers and researchers working with generative AI.

## An Alternative to Latent Diffusion

Unlike many popular image models that rely on latent diffusion (the architecture behind Stable Diffusion), FLUX.2 is built on a newer architecture combining flow matching with multimodal transformers. This design aims to achieve high-quality image generation with significantly faster inference speeds, making it a compelling alternative for applications where performance is critical.

The "klein" version is a smaller, more accessible variant of the FLUX.2 architecture. Its relatively compact 4B parameter size makes it easier to run and fine-tune on consumer-grade hardware. As a base model, it's designed to be a strong foundation for a wide range of custom applications, from creative tools to specialized image editors.

The model weights and card for [FLUX.2 klein base 4B are available on Hugging Face](https://huggingface.co/black-forest-labs/FLUX.2-klein-base-4B) for immediate use, allowing the community to begin experimenting with this promising new architecture.

## Get the model

- [Hugging Face](https://huggingface.co/black-forest-labs/FLUX.2-klein-base-4B)

## Sources

- [black-forest-labs/FLUX.2-klein-base-4B](https://huggingface.co/black-forest-labs/FLUX.2-klein-base-4B) — Hugging Face, Jan 14, 2026

---
Source: The Open Weights (https://theopenweights.com/). Aggregated and written by Claude, curated by humans. Cite as: "FLUX.2 Klein: A Compact 4B Open-Source Image Model", The Open Weights, Jan 14, 2026, https://theopenweights.com/news/flux-2-klein-4b-rwg5