What is a negative prompt?

By Updated 2 min read

A negative prompt is a second text field where you list what the image must not contain: blur, extra fingers, watermarks, text, ugly colours. Stable Diffusion steers the generation away from those concepts at every step, which improves quality faster than adding more words to the main prompt.

How it works

At each denoising step the model computes two predictions: one guided by your prompt, one guided by the negative prompt. The final direction is the first minus the second, scaled by the CFG value. So the negative prompt is not a filter applied at the end: it shapes the image from the first step. That is also why a negative prompt without a CFG above 1 has no effect.

Negative prompts that work

General quality (SD 1.5, SDXL):

blurry, low quality, lowres, jpeg artifacts, watermark, text, signature, cropped, out of frame

People and portraits:

deformed, bad anatomy, extra fingers, missing fingers, extra limbs, mutated hands, poorly drawn face, asymmetric eyes

Photography:

painting, drawing, illustration, cartoon, 3d render, cgi, oversaturated, overexposed

Anime and illustration:

photorealistic, photo, realistic skin, worst quality, normal quality, monochrome

Start with the general list and add the block that matches your goal. Ten to twenty terms are plenty; long copied lists mostly add noise.

Weights in the negative prompt

Weights work exactly as in the main prompt: (blurry:1.4) pushes harder away from blur, (text:1.2) removes stray letters. Raise a weight only for a defect that keeps coming back; above 1.5 the model starts distorting other things to obey.

When it does nothing

  • CFG scale at 1: the negative prompt is ignored by construction. Use 5 to 8.
  • Turbo and LCM models (SDXL Turbo, LCM LoRA) run at CFG 1 to 2 and barely react to negatives.
  • Stable Diffusion 3 and 3.5 use the negative prompt weakly; write the positive prompt more precisely instead.
  • Concepts the model cannot separate: "no hands" in the negative removes hands from view, it does not fix hand anatomy. Inpainting does.

On this site

The inpainting tool already applies a strong negative prompt behind the scenes, so you only describe what you want. The prompt examples show the negative prompt used for each image next to the positive one; copy both to reproduce a result, then change one term at a time with a fixed seed.

Questions people also ask

Is a negative prompt mandatory?

No. SDXL and SD 3 produce good images without one. It becomes valuable for portraits, hands, photorealism, and to kill a recurring defect such as watermarks or text.

Can I put 'nsfw' in the negative prompt?

Yes, and it is a common way to keep SD 1.5 fine-tunes safe. Keep in mind that adult content and violence are not allowed anywhere on this site, whatever the negative prompt says.

Does the order of words matter in the negative prompt?

Slightly: the first terms weigh a little more, exactly as in the positive prompt. Put the defect you care most about first.