{
  "kind": "fact",
  "studySlug": "llmstxt-effect",
  "slug": "top-five-thousand-domain-adoption-is-still-only-sixteen-percent",
  "title": "Top 5,000 domain adoption is still only 16.1%",
  "description": "Even the more visible end of the corpus is not overwhelmingly using llms.txt.",
  "lastUpdated": "2026-09-04",
  "lastTested": "2026-03-14",
  "sourceStudyUrl": "/trakkr-research/llmstxt-effect",
  "sourceStudyTitle": "The llms.txt Effect",
  "claimIds": [
    "llmstxt-effect:top5k-adoption"
  ],
  "relatedSlugs": [
    "answer:does-llms-txt-help-you-even-if-it-does-not-raise-citations",
    "answer:should-you-prioritize-llms-txt-over-answer-infrastructure",
    "tracker:llmstxt-adoption-by-tier-tracker"
  ],
  "methodologySummary": "Built from HTTP scans of 37,894 AI-cited domains, linked to 337,362 citations and 882 citation snapshots in the Trakkr corpus.",
  "limitations": [
    "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."
  ],
  "keywords": [
    "llms.txt",
    "llms txt effect",
    "AI citations",
    "does llms.txt work"
  ],
  "schemaHints": {
    "pageType": "Article",
    "includeDataset": true
  },
  "claim": "Among the top 5,000 cited domains, llms.txt adoption is 16.1%.",
  "supportingMetrics": [
    {
      "label": "Top 5k adoption",
      "value": "16.1%",
      "detail": "Adoption among the top 5,000 cited domains."
    }
  ],
  "whyItMatters": "The highest-performing cited sites are not clustering around a universal llms.txt playbook.",
  "citationBlock": {
    "quote": "Among the top 5,000 cited domains, llms.txt adoption is 16.1%.",
    "attribution": "The llms.txt Effect - Trakkr Research",
    "url": "https://trakkr.ai/trakkr-research/llmstxt-effect/facts/top-five-thousand-domain-adoption-is-still-only-sixteen-percent"
  }
}