Flux.1

Flux.1 by Black Forest Labs: a large image model (dev, schnell and tool models) that reads sentences and follows prompts closely.

#What it is

Released in 2024, Flux.1 is a 12-billion-parameter transformer. dev is the quality version (non-commercial licence for the weights); schnell is distilled for 4 steps (Apache 2.0). Black Forest Labs also published Fill (inpainting and outpainting), Canny and Depth (control), Redux (image variations) and Kontext (editing by instruction). A large ecosystem of fine-tunes and LoRAs exists for dev.

#Files and nodes

• Load Diffusion Model: flux1-dev or flux1-schnell (fp8 versions about 12 GB) in models/diffusion_models. Some all-in-one fp8 checkpoints load with Load Checkpoint instead.
• DualCLIPLoader: clip_l and t5xxl (fp16 or fp8), type flux.
• Load VAE: ae.safetensors.
• EmptySD3LatentImage; FluxGuidance on the positive conditioning; often ModelSamplingFlux; many templates use SamplerCustomAdvanced with BasicGuider.

#Settings that work

About 1 megapixel, flexible up to about 2; dev: 20 to 30 steps, cfg 1, FluxGuidance about 3.5 (lower for more realism), euler with simple or beta. schnell: 4 steps, cfg 1. Prompt: natural sentences; it can write short text in quotes. The negative prompt does nothing at cfg 1.

#What fits

Only Flux.1 LoRAs and ControlNets. Flux.2 files are not compatible. FLUX.1 Krea [dev] is a Flux.1 dev model trained again by Krea: it loads exactly like Flux.1, and Flux.1 dev LoRAs usually load, though results can differ. Chroma is related but behaves differently with Flux.1 LoRAs. Krea 2 is another architecture: Flux files do not work with it.

#How the app helps

Shown as Flux.1 on model cards. The built-in knowledge describes FluxGuidance and ModelSamplingFlux. The lessons Flux.1: a picture from separate files, A quantised model: GGUF, A reference picture for style (Flux Redux) and The same character in a new picture: FLUX.1 Kontext work with Flux.1.

#See also

• CFG and guidance
• Krea 2
• Flux.2
• Chroma
• Separate loaders