Not sure where to start? Take a guided tour.
AI Site Grader
AI Query Scanner
llms.txt GeneratorHow common is llms.txt on AI-cited domains?
It is still uncommon. Only 13.3% of the 37,894 scanned AI-cited domains had an llms.txt file.
The key numbers.
- Domains scanned
- AI-cited domains scanned for llms.txt.
- 37,894
- Adoption rate
- Domains with llms.txt in the study.
- 13.3%
- Domains with llms.txt
- Absolute adoption count.
- 5,035
Adoption exists, but it is nowhere close to universal and remains concentrated in specific sectors.
The evidence.
Source
The llms.txt Effect
| Measure | Result |
|---|---|
| Domains scanned AI-cited domains scanned for llms.txt. | 37,894 |
| Adoption rate Domains with llms.txt in the study. | 13.3% |
| Domains with llms.txt Absolute adoption count. | 5,035 |
Population and method
Built from HTTP scans of 37,894 AI-cited domains, linked to 337,362 citations and 882 citation snapshots in the Trakkr corpus.
Where the evidence stops
This is an observational study. It measures correlation with citation outcomes, not a controlled experiment.
Adoption is uneven by sector, so raw averages can hide category concentration in SaaS and developer tooling.
The top-5,000 test returns p=0.85. The full scanned sample returns p<0.001 with reported r=-0.065. Neither establishes a causal effect. The public aggregates do not include confidence intervals or document the cohort for citation means and medians well enough to recompute the tests.
What to do with this
- Treat llms.txt as an optional housekeeping file, not a primary citation-growth lever.
- Prioritize answer quality, source coverage, and page structure before spending disproportionate effort on llms.txt.
- If you do publish llms.txt, measure discovery and crawl behavior directly instead of assuming it improved citation performance.
This answer matters because it turns a study finding into an operating rule teams can use when they decide what to publish, refresh, or measure next.
Questions about this answer.
Cite this answer.
Source study: llms.txt Effect“It is still uncommon. Only 13.3% of the 37,894 scanned AI-cited domains had an llms.txt file.”
Mack Grenfell · How common is llms.txt on AI-cited domains?
The llms.txt Effect · Trakkr Research · Updated 4 September 2026