FLUX 3 Image Klein released, a 5.6B open-weights model from $0.008 per image

FLUX 3 Image Klein is a 5.6B parameter version of FLUX 3 Image with open weights. It supports the same features: text to image, image editing, multi reference, and bounding boxes. Run it through the API, download the weights from Hugging Face, or load it in ComfyUI.

Key Features

• Same request as FLUX 3 Image: prompt, images, aspect_ratio, resolution, and the bounding box format are unchanged. A FLUX 3 Image request runs on Klein by switching the endpoint
• Two variants: Klein (Distilled) runs 16 steps at CFG 1 for fast inference. Klein Base runs 50 steps at CFG 3.5 and is the model for fine-tuning and LoRA training
• Open weights: both variants are on Hugging Face under the FLUX Kommunity License and run on consumer GPUs, down to an RTX 3090
• Up to 4K output: resolution from 768sq to 4k, with up to ten reference images per request
• LoRA training: train on Klein Base with AI Toolkit (arch: flux3) or Diffusers. The trained LoRA also loads into Klein (Distilled)

Pricing

Per image, by resolution. Text to image and image editing cost the same.

| resolution | Price | | - | - | | 768sq | $0.008 | | 1k | $0.009 | | 1.5k | $0.011 | | 2k | $0.014 | | 4k | $0.036 |

Endpoint

FLUX 3 Image Klein API reference

Weights

• FLUX 3 Image Klein (Distilled)
• FLUX 3 Image Klein Base
• ComfyUI weights and the ComfyUI Klein workflow

Start with the FLUX 3 Image Klein overview.