llms.txt in 2026: 10% adoption, few crawler hits
llms.txt keeps spreading, but the evidence that AI systems read it is thin. Here is what the 2026 data says and when the file is still worth having.
The llms.txt file, a Markdown map of a site for language models, became much more common in 2026. Whether anything reads it is another question.
What happened
- Adoption: an SE Ranking analysis of about 300,000 domains put adoption near 10%. Ahrefs reported adoption up 8.8 times year over year in a separate study.
- Requests: Ahrefs’ server-log data found 97% of llms.txt files got zero requests from AI crawlers in the study month. Another study across 500 million AI bot visits counted only 408 direct requests for the file in 90 days. Profound, on the other hand, reported Microsoft and OpenAI crawlers fetching llms.txt and llms-full.txt.
- Google: its guidance says Google Search doesn’t use llms.txt. Google did add an llms.txt check to Lighthouse in May 2026.
No public study shows a measurable link between llms.txt and AI citations.
What it means for you
- It’s cheap, so it’s fine to have, especially for documentation, APIs and developer tools, where coding assistants and agents may read it when a user points them at your site.
- Don’t expect ranking or citation gains. Crawlable HTML, clear structure and allowed bots matter far more.
- If you publish one, keep it valid and current. A broken or outdated file is worse than none.
Create one with the llms.txt Generator and check it with the llms.txt Validator.