Pushing Toward the Prompt

Classifier-free guidance strengthens prompt adherence by running the denoiser twice at each step: once with the prompt conditioning and once without it. The two noise predictions are combined by extrapolating away from the unconditional one, using a guidance scale. A scale of one means no guidance — the output is the conditional prediction alone. Higher scales push the result further toward the prompt, which improves alignment but reduces diversity and can over-saturate colors or freeze motion. Lower scales allow more variation but drift from the prompt. The guidance scale is therefore a direct trade-off knob between prompt adherence and naturalness.