TL;DR Contents Getting started What FLUX.3 can do Text-to-image Image-to-image Layout control Base model and quantized variants Base model Single-file format checkpoints LoRA finetuning What it costs to run Memory Speed The architecture From pixels to tokens From prompt to tokens Two stages Inside one block Every token gets its own timestep Positions in four dimensions The denoising loop Modular Diffusers See the workflows Encode once, generate many Add a step inside the loop Try it Black Forest Labs FLUX.3 Image Klein is here, and it runs in Diffusers from day one. One model does text-to-image and multi-reference image-to-image, and it adds something new, the layout control. You write bounding boxes into the prompt to say where each part of the image should go, or which parts of a reference image to move.