Not sure where to start? Take a guided tour.
AI Site Grader
AI Query Scanner
llms.txt GeneratorDo brands need third-party sources to win AI citations?
This index alone cannot answer that. It aggregates cited domains but does not label ownership for every URL or provide an experimental comparison between owned-only and third-party strategies.
The key numbers.
- Reference category share
- Partial hand-maintained source classification.
- 1.48%
- Social category share
- Social is the largest named category, led by YouTube, Reddit, and LinkedIn.
- 6.11%
- Review category share
- Partial hand-maintained source classification.
- 1.11%
- Unique domains
- Distinct normalized domains in the current brand snapshots.
- 725,777
Use the domain index to see which third parties appear for tracked prompts, then test whether those sources matter for the brand in question.
The evidence.
Source
AI Citation Index
| Measure | Result |
|---|---|
| Reference category share Partial hand-maintained source classification. | 1.48% |
| Social category share Social is the largest named category, led by YouTube, Reddit, and LinkedIn. | 6.11% |
| Review category share Partial hand-maintained source classification. | 1.11% |
| Unique domains Distinct normalized domains in the current brand snapshots. | 725,777 |
Population and method
Built from 80,769,585 citation appearances across 725,777 unique domains in the latest valid snapshot for 1,928 tracked brands, observed from October 3, 2025 to October 14, 2026.
Where the evidence stops
The index is a changing panel of tracked brands and prompts, not a random sample of all AI responses.
Domain share is observational. It does not establish causal influence or reveal the full retrieval set.
The hand-maintained source taxonomy is partial: 88.40% of citation appearances remain in “other”.
Model attribution, response-level citation denominators, geography, raw prompts, and raw responses are not retained in the public aggregate.
What to do with this
- 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.
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.
Questions about this answer.
Cite this answer.
Source study: Citation Sources“This index alone cannot answer that. It aggregates cited domains but does not label ownership for every URL or provide an experimental comparison between owned-only and third-party strategies.”
Mack Grenfell · Do brands need third-party sources to win AI citations?
AI Citation Index · Trakkr Research · Updated 14 October 2026