FLUX: The Image Model Family Built by Stable Diffusion's Original Team, from 12B to a Self-Flow World Model
FLUX is Black Forest Labs' image-model family. The Stable Diffusion team launched it in August 2024 with a 12B rectified-flow transformer. Two years later it spans klein 4B ($0.014 and the only current Apache-2.0 model) / 9B, pro ($0.03), flex ($0.05), max ($0.07 with live web grounding), and open-weight 32B dev. FLUX 3 extends Self-Flow to video, synchronized audio, and robot actions. This guide covers the FLUX.1-to-FLUX 3 evolution, three-tier licensing, and model selection.