Study 02 · Supporting Market Volume · United States

llms.txt Adoption in United States

A descriptive market breakdown. These figures show what United States looked like; what the study demonstrates — that llms.txt adoption does not predict AI-crawler openness — is established in the pooled cross-market benchmark, where the sample supports inference.

Research instrumentPTODA C01 Crawler v1.3
Scan date17 June 2026
Sample808 domains · 758 scannable · 129 adopters
17.0%
of scannable United States businesses have adopted llms.txt

129 of 758 scannable domains publish llms.txt, of which 96.1% are valid files. The United States shows the highest adoption volume and the highest conformance — but also the highest observed contradiction rate: nearly half of US adopters block the crawlers they guide.

The market figures

Adoption, conformance, contradiction, and the reconfirmed access benchmark for United States — all drawn from the pooled study tables.

17.0%
llms.txt adoption
129 of 758 scannable domains.
96.1%
Conformance of adopters
124 of 129 published a valid file.
43.4%
Contradiction (observed)
56 of 129 adopters also block AI crawlers.
42.2%
Access benchmark
261 / 619 domains with an observable policy block at least one AI retrieval crawler. Reconfirms the frozen v1.2 figure.
129
Adopters observed
The llms.txt adopter count for United States — the paired-analysis base for this market.
758
Scannable domains
Domains where the relevant layer could be observed (denominator).

Interpretation note

Descriptive, not inferential. This market-level report is descriptive. The number of llms.txt adopters observed within a single market is insufficient to support independent statistical inference regarding the relationship between llms.txt adoption and AI-crawler access. The inferential finding for this study is reported in the pooled four-market benchmark, which combines all observable domains into a single paired analysis (n = 1,617).

This separation is deliberate. A single market's adopter sample is too small for its contradiction rate to be read as a proven market effect — United States’s 43.4% is observed, not demonstrated. For the hypothesis test, the null result, the effect size, and the interpretation, see the pooled AI Accessibility & Machine-Readable Guidance Benchmark, which carries all inferential claims for this study.