The most-cited domains in AI answers

Every time an AI answer engine cites a source, it is deciding whose page is trustworthy enough to repeat. Add those decisions up and a clear order appears, with most citations going to the very top.

Inside the top 100 source domains, the two most-cited sites alone carry 32.3% of all citations, and the top 10 carry 58.7%. The long list of sites below them splits what is left.

The most-cited domain is not a newsroom or an encyclopedia. It is YouTube, with 60,164 citations across the window, appearing in 9,370 different prompts. AI engines reach for video pages as evidence more than any other source.

Reddit ranks second with 55,505 citations, just behind YouTube. But it appears in more prompts than any other domain, 11,622, and touches 74,716 different brands. When AI wants a human take, it reads the forum.

Ranking the ten most-cited domains by citation volume, user-generated platforms and a single encyclopedia lead. The first traditional newsroom, Forbes, sits in fourth, and it is the only pure publisher in the top ten.

Group the top 100 domains by what they are and one category is far larger than the rest. Community and social platforms, the forums, video sites, and networks where ordinary people post, carry 44.8% of all citations in the cut.

That is more than the next two categories, news and publishers (18.0%) and knowledge and research (10.6%), combined.

Eight community and social domains carry 160,630 citations between them. Thirty-one news and publisher domains, nearly four times as many sites, share 64,599. Per domain, the gap is even wider.

Below the platforms sits a smaller group of reference and research sites. Wikipedia leads it with 24,875 citations, third overall. The ten knowledge and research domains together account for 10.6% of citations, steady but well behind the community platforms.

The ranked table shows each leading domain with its citation count, the number of different prompts it appears in, and the number of different brands it touches. Sort by any column to see how reach and depth differ.

Citation volume measures how often a domain is quoted. Brand reach measures how many different brands it touches. Reddit reaches more brands than YouTube even though it trails on raw citations, while a finance site like NerdWallet is cited often but across a narrow set of brands.

The most-cited domain carries 60,164 citations. The hundredth, Ramp, carries 837. That is a roughly 72-to-1 gap inside a list that already excludes the millions of domains cited less often than the top 100. Visibility drops off quickly below the top ranks.

Below the big platforms, the categories sit close together. Ten commerce and app-store domains carry 8.6% of citations, ahead of the fourteen software and review domains at 4.9%. Marketplaces where buyers transact get cited more than the directories built to Compare products.

Find the main sources for your category. If your buyers ask the kind of question that pulls community answers, your presence on the forum or video platform matters more than a press hit.

Do not focus only on the very top. The two leading domains are general-purpose. The source that decides your category is more often a mid-list domain that AI trusts for your specific questions.

A citation comes before a recommendation. AI recommends brands it can find evidence for. The domains it cites are where that evidence lives.

We took the top 100 source domains by citation count from a public-index snapshot of AI answer citations across ChatGPT Search and Google AI Mode, dated April 21, 2026. For each domain we counted total citations, the number of different prompts it appeared in, and the number of different brands it was associated with, then hand-labeled each domain into a source category.

Shares are computed within this top-100 cut, not across the whole web, so they describe how citations concentrate among the most-cited sources rather than across all citations everywhere. A citation records that an engine pointed to a page, not whether it agreed with it or disputed it. Figures describe an observed sample from the two engines we measured, not Perplexity, Gemini, or Copilot.