# What source categories show up most in AI answers? | Trakkr Research

Canonical URL: https://trakkr.ai/trakkr-research/citation-sources/answers/what-source-categories-show-up-most-in-ai-answers
Published: 2026-04-17
Last updated: 2026-04-17
Author: Mack Grenfell

Reference and social are the clearest named categories, while the long tail still absorbs most citations.

## 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, the long tail absorbs citations at 84.51%, while reference and social are the clearest named categories. Reference sources hold 6.75%, social holds 3.82%, reviews hold 0.89%, and docs hold 0.20%.

## What this means

Operators must allocate resources based on category share to determine what content types to publish, refresh, or measure next for optimal AI visibility.

## Evidence table

| Metric | Value | Why it matters |
| --- | --- | --- |
| Reference category share | 6.75% | Reference sites are the largest named category in the current index. |
| Social category share | 3.82% | Social sources matter materially, led by YouTube, Reddit, and LinkedIn. |
| Review category share | 0.89% | Reviews are smaller in raw share but disproportionately commercial. |
| Docs category share | 0.20% | Docs are cited less often overall, but they show up in technical query classes. |
| Long-tail share | 84.51% | Most citations are spread across a very large long tail of domains. |

## Frequently Asked Questions

### How much of the citation share belongs to the long tail?

Most citations are spread across a very large long tail of domains, accounting for 84.51% of the total share.

### Which named category receives the highest citation share?

Reference sites are the largest named category in the current index, holding a 6.75% share.

### Are review sites significant despite their low overall share?

Reviews hold a 0.89% share, which is smaller in raw share but disproportionately commercial.

## What to do next

- [Audit the domains that already dominate your category and decide which ones are realistic citation targets.](https://trakkr.ai/trakkr-research/citation-sources/answers/what-source-categories-show-up-most-in-ai-answers#next-step-1)
- [Build source-worthy pages for the query shapes where AI is already citing third parties.](https://trakkr.ai/trakkr-research/citation-sources/answers/what-source-categories-show-up-most-in-ai-answers#next-step-2)
- [Treat reference, review, and social sources as part of your AI visibility surface rather than noise.](https://trakkr.ai/trakkr-research/citation-sources/answers/what-source-categories-show-up-most-in-ai-answers#next-step-3)

## Related pages

Continue through the same study cluster.

- [do brands need third party sources to win ai citations](https://trakkr.ai/trakkr-research/citation-sources/answers/do-brands-need-third-party-sources-to-win-ai-citations) - Related answer page
- [what should a brand prioritize after reading the source data](https://trakkr.ai/trakkr-research/citation-sources/answers/what-should-a-brand-prioritize-after-reading-the-source-data) - Related answer page
- [wikipedia leads the current citation index](https://trakkr.ai/trakkr-research/citation-sources/facts/wikipedia-leads-the-current-citation-index) - Related fact page
- [source category share tracker](https://trakkr.ai/trakkr-research/citation-sources/trackers/source-category-share-tracker) - Related tracker page

## Data And Sources

- [Where AI Gets Its Answers](https://trakkr.ai/trakkr-research/citation-sources) - Flagship study behind this page
- [Page JSON](https://trakkr.ai/data/research-answers/citation-sources/answers/what-source-categories-show-up-most-in-ai-answers.json) - Machine-readable companion file