Learn Diffusion
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Lesson 5 • 2 min

CFG Scale

The creativity vs accuracy dial

How literally to follow instructions

If you ask an artist for "a cat", they might paint anything from a photorealistic portrait to an abstract interpretation. CFG (Classifier-Free Guidance) scale controls how literally the model follows your prompt.

Adjust CFG scale and see how outputs change

Low CFG (1-3): More creative, diverse outputs, might drift from prompt. High CFG (10-20): Strictly follows prompt, but can look "overcooked" or artificial. Sweet spot is usually 7-9.

CFG scale effects
CFG Scale Effects:

1.0  → Ignores prompt, random generation
3.0  → Loose adherence, very creative
7.0  → Balanced (default for most models)
12.0 → Strong adherence, less variety
20.0 → Over-saturated, artifacts likely

Z-Image-Turbo uses CFG=0 (!)
It was trained to not need CFG—the guidance
is "baked in" during distillation.

Quick Win

Module 3 complete! You understand the full diffusion process: forward noise addition, reverse denoising, Gaussian math, text guidance, and CFG scale.