Which sources dominate AI citations? | Trakkr Research
The short answer is that a small set of domains dominates the head while the long tail still matters.
Methodology: 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.
Direct Answer
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.
What this means
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.
Evidence table
| Metric | Value | Why it matters |
|---|---|---|
| Wikipedia share | 6.43% | en.wikipedia.org alone accounts for 564,191 citations. |
| Reference category share | 6.75% | Reference sites are the largest named category in the current index. |
| Long-tail share | 84.51% | Most citations are spread across a very large long tail of domains. |
| Citations analyzed | 8.78M | Current live citation index as of April 17, 2026. |
Frequently Asked Questions
How much of the citation share does Wikipedia control?
Wikipedia accounts for 6.43 percent of all citations, with en.wikipedia.org alone generating 564,191 citations in the current index.
What percentage of citations fall into the long tail?
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.
What to do next
Related pages
Continue through the same study cluster.
- how concentrated is the ai citation landscape - Related answer page
- does ai rely more on reference sites than the open web - Related answer page
- wikipedia leads the current citation index - Related fact page
- source category share tracker - Related tracker page
Data & Sources
- Where AI Gets Its Answers - Flagship study behind this page
- Page JSON - Machine-readable companion file