{
  "kind": "answer",
  "studySlug": "citation-sources",
  "slug": "which-sources-dominate-ai-citations",
  "title": "Which sources dominate AI citations?",
  "description": "The short answer is that a small set of domains dominates the head while the long tail still matters.",
  "lastUpdated": "2026-04-17",
  "lastTested": "2026-04-17",
  "sourceStudyUrl": "/trakkr-research/citation-sources",
  "sourceStudyTitle": "Where AI Gets Its Answers",
  "claimIds": [
    "citation-sources:wikipedia-share",
    "citation-sources:reference-share",
    "citation-sources:other-share",
    "citation-sources:total-citations"
  ],
  "relatedSlugs": [
    "answer:how-concentrated-is-the-ai-citation-landscape",
    "answer:does-ai-rely-more-on-reference-sites-than-the-open-web",
    "fact:wikipedia-leads-the-current-citation-index",
    "tracker:source-category-share-tracker"
  ],
  "methodologySummary": "Built from the live citation index backing Trakkr Research, using 8,777,687 citations across 208,567 unique domains observed between October 3, 2025 and April 17, 2026.",
  "limitations": [
    "The live citation index is broader than the original December 2025 launch study, so percentages here should be read as the current benchmark.",
    "Domain share does not mean causal influence. It measures what models cited, not the full retrieval set.",
    "Category totals are domain-level rollups and may hide differences by model or query intent."
  ],
  "keywords": [
    "AI citations",
    "citation sources",
    "AI source preferences",
    "domain authority in AI",
    "dominant AI sources",
    "top AI citation sources"
  ],
  "schemaHints": {
    "pageType": "Article",
    "includeDataset": true
  },
  "question": "Which sources dominate AI citations?",
  "directAnswer": "Mostly, a concentrated set of reference domains dominates the head of AI citations. Wikipedia leads with 6.43 percent of all citations, while the reference category as a whole captures 6.75 percent of the 8.78M citations analyzed.",
  "answerSummary": "AI models do not sample the web evenly. They rely heavily on a concentrated head of reference sites for foundational facts, leaving a highly fragmented long tail of niche, commercial, and editorial domains to supply the remaining 84.51 percent of citations.",
  "keyFacts": [
    {
      "label": "Wikipedia share",
      "value": "6.43%",
      "detail": "en.wikipedia.org alone accounts for 564,191 citations.",
      "claimId": "citation-sources:wikipedia-share"
    },
    {
      "label": "Reference category share",
      "value": "6.75%",
      "detail": "Reference sites are the largest named category in the current index.",
      "claimId": "citation-sources:reference-share"
    },
    {
      "label": "Long-tail share",
      "value": "84.51%",
      "detail": "Most citations are spread across a very large long tail of domains.",
      "claimId": "citation-sources:other-share"
    },
    {
      "label": "Citations analyzed",
      "value": "8.78M",
      "detail": "Current live citation index as of April 17, 2026.",
      "claimId": "citation-sources:total-citations"
    }
  ],
  "evidenceTable": [
    {
      "label": "Wikipedia share",
      "value": "6.43%",
      "note": "en.wikipedia.org alone accounts for 564,191 citations."
    },
    {
      "label": "Reference category share",
      "value": "6.75%",
      "note": "Reference sites are the largest named category in the current index."
    },
    {
      "label": "Long-tail share",
      "value": "84.51%",
      "note": "Most citations are spread across a very large long tail of domains."
    },
    {
      "label": "Citations analyzed",
      "value": "8.78M",
      "note": "Current live citation index as of April 17, 2026."
    }
  ],
  "whyItMatters": "Operators must allocate resources based on actual citation distribution. Knowing that reference sites dominate the head allows teams to prioritize third-party placements on high-yield domains rather than relying solely on owned properties for AI visibility.",
  "whatToDo": [
    "Audit the domains that already dominate your category and decide which ones are realistic citation targets.",
    "Build source-worthy pages for the query shapes where AI is already citing third parties.",
    "Treat reference, review, and social sources as part of your AI visibility surface rather than noise."
  ],
  "faqs": [
    {
      "question": "How much of the citation share does Wikipedia control?",
      "answer": "Wikipedia accounts for 6.43 percent of all citations, with en.wikipedia.org alone generating 564,191 citations in the current index."
    },
    {
      "question": "What percentage of citations fall into the long tail?",
      "answer": "Most citations are spread across a very large long tail of domains, which accounts for 84.51 percent of the 8.78M citations analyzed as of April 17, 2026."
    }
  ]
}