Flux: The Next Generation

Overview

Flux is an image generation model by Black Forest Labs, the founding team behind Stable Diffusion. Released mid-2024, it represents a major quality leap over SDXL.

Flux Variants

  • Flux.1 Dev: non-commercial, full version
  • Flux.1 Schnell: Apache 2.0, fast (4 steps)
  • Flux.1 Pro: API only, commercial

Why Flux is Superior

  • Readable text in images
  • Better prompt following
  • Photorealistic quality
  • Better human anatomy
  • Superior composition understanding

ComfyUI Configuration

Flux uses separate model loading: Load Diffusion Model + DualCLIPLoader + Load VAE.

Recommended Parameters

  • sampler: euler, scheduler: simple
  • Flux Dev: 20-30 steps, Flux Schnell: 4 steps
  • cfg: 1.0 (guidance via FluxGuidance node, typically 3.0-4.0)

VRAM Optimization

  • Use quantized models (FP8, NF4/GGUF)
  • T5 encoder in FP8
  • --lowvram flag
  • CPU offloading

LoRAs, ControlNet, and img2img

All work similarly to SD but with Flux-specific models and configurations. LoRAs are larger (~100-500 MB). ControlNet support is newer but growing.