LLM Smells: How AI-Assisted Writing Develops Recognizable Patterns Across the Web

Late last year, the author started a math blog and used LLMs to polish and enhance their writing. At first, the LLM-generated text felt significantly better than their own drafts—richer vocabulary, more interesting sentence structures, and none of the obvious signs of AI slop. But three months later, they noticed the exACT Same sentence structures APPearing everywhere across the internet.

What stood out was how certain “AI smells” emerge as recognizable artifacts across different AI-assisted tasks. Below are examples from two domains:

1. LLM Writing (beyond the obvious em-dashes)

Examples from the author’s now-deleted math blog and associated drafts:

• Too many punchlines
  “Humans trust symmetry because it feels like intelligence made visible.”
  “The Tiger fit the story. Jin-yong fit the physics.”
  “Symmetry becomes a trap.”

• ConSECutive short sentences
  “Yet the tilt is not an accident. It is the shape of the optimum.”
  “Then AlphaEvolve ARRived. It had no preference for symmetry. No Aesthetic prior. No instinct to preserve hArmony.”
  “These examples are not decorative. They form a distributed argument.”

• "X is the Y of Z" structure
  “Cringe is the visible signature of moving along a gradient you chose.”

• "Not just X, it’s Y" structure
  “solutions that do not merely satisfy the constraint but satisfy the aesthetic instincts.”

2. AI-Generated Websites

Common visual patterns include:

• Widespread use of JetBrains Mono font

• Consistent step indicators and bullet points using that exact font

• Nearly identical button designs across unrelated AI-generated sites

These patterns make AI-assisted content increasingly recognizable, even when the text itself avoids obvious slop.