debru · AI images

Negative prompts in SDXL: do you need them?

October 4, 2026

In older models (SD 1.5) a negative prompt was almost mandatory. For SDXL I had doubts, so I tested it. My usual negative:

lowres, blurry, jpeg artifacts, watermark, text, signature, deformed, extra limbs

Same seed and everything else; left without the negative, right with it.

portrait of an old shepherd dog, studio light, photorealistic
without
portrait of an old shepherd dog, studio light, photorealistic
with negative

Dog portrait: both are fine. With the negative the fur is a bit crisper and the expression changed (mouth slightly open), but whether that's “better” is a matter of taste.

a city street at night in the rain, neon signs
without
a city street at night in the rain, neon signs
with negative

Rainy night street: with the negative there's more detail and people with umbrellas appeared. But text in the negative did not remove the pseudo-glyphs on the signs — because I'm asking for neon signs in the prompt myself, and the model can't really imagine signs without lettering.

Conclusion

  • In SDXL a negative prompt isn't a magic “quality” button, just another way to nudge the image.
  • It can't cancel what follows directly from the main prompt.
  • I keep a short negative by default, but don't expect miracles and always check the version without it.