Google said llms.txt does nothing. I checked what 137,210 domains actually got.

Description and use

llms.txt does not boost AI search visibility, as confirmed by Google and four independent studies.

Problem

Site owners believed llms.txt would improve AI search visibility, but evidence shows it has negligible impact.

Outcome

All studies and Google documentation confirm llms.txt has no measurable effect on AI search visibility; it is a developer documentation tool, not an SEO tactic.

Workflow

• 1. Build an audit tool to detect llms.txt.
• 2. Collect data from Ahrefs, SE Ranking, OtterlyAI, and Limy on llms.txt presence and bot traffic.
• 3. Analyze traffic patterns and correlation with AI visibility.
• 4. Update audit tool to flag llms.txt without scoring it.
• 5. Focus on content-level signals (crawlability, citations, semantic structure).

Evidence

You don't need to create new machine readable files, AI text files, markup, or Markdown to appear in generative AI search.

Source

AFAIK none of the AI services have said they're using LLMs.TXT (and you can tell when you look at your server logs that they don't even check for it).

Source

28% of the 137,210 domains publish an llms.txt file (about 38,000 sites). 97% of those files received zero traffic in May 2026.

Source

The largest single research crawler in the dataset identified itself as prompt-injection-survey/1.0.

Source

OtterlyAI ran a controlled experiment over 90 days. 84 of 62,100+ AI bot visits targeted /llms.txt.

Source

Limy's analysis monitored 515,382,577 AI bot traffic events over a 90‑day window. 408 requests targeted /llms.txt directly.

Source