How concentrated is the AI citation landscape? | Trakkr Research
The top three domains account for 7.04% of citation appearances, while the index spans 529,165 unique domains and 2.60 million cited URLs. That is a visible head followed by a very broad tail.
Methodology: Built from 48,422,016 citation appearances across 529,165 unique domains in the latest valid snapshot for 1,643 tracked brands, observed from October 3, 2025 to August 18, 2026.
Direct Answer
The top three domains account for 7.04% of citation appearances, while the index spans 529,165 unique domains and 2.60 million cited URLs. That is a visible head followed by a very broad tail.
What this means
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.
Evidence table
| Metric | Value | Why it matters |
|---|---|---|
| Top three domain share | 7.04% | YouTube, English Wikipedia, and Reddit together account for 7.04%. |
| Unique domains | 529,165 | Distinct normalized domains in the current brand snapshots. |
| Unique cited URLs | 2.60M | 2,602,557 distinct cited URLs in the current snapshot. |
| Unclassified share | 86.75% | Domains outside the current named source map remain in “other”. |
Frequently Asked Questions
How concentrated is the AI citation landscape?
The top three domains account for 7.04% of citation appearances, while the index spans 529,165 unique domains and 2.60 million cited URLs. That is a visible head followed by a very broad tail.
Which numbers from AI Citation Index matter most here?
Top three domain share: 7.04%. YouTube, English Wikipedia, and Reddit together account for 7.04%. Unique domains: 529,165. Distinct normalized domains in the current brand snapshots.
What should a team do next?
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, not as noise.
What to do next
Related pages
Continue through the same study cluster.
- does ai rely more on reference sites than the open web - Related answer page
- does social content matter for ai citations - Related answer page
- the citation graph spans more than two hundred thousand domains - Related fact page
- top cited domain tracker - Related tracker page
Data & Sources
- AI Citation Index - Flagship study behind this page
- Page JSON - Machine-readable companion file