Top 100 Most-Cited Domains in AI Search: Q4 2026

Which domains did five AI engines cite most?

YouTube led Foglift’s frozen Q4 2026 panel, appearing in 72 of 375 answers (19.2%). Forbes ranked second at 62 answers (16.5%), followed by Reddit at 43 (11.5%), G2 at 31 (8.3%), and Healthline at 22 (5.9%). The complete table publishes the top 100 of 1,411 measured domains.

Headline findings

Source visibility remained engine-specific. The five engine top-25 lists contained 84 domains in total. Of those, 55 appeared in only one engine's top 25, and none appeared in all five. The mean pairwise cited-domain overlap was 0.103. One engine's authority map still cannot stand in for the other four.

Top 100 cited domains across five AI engines

Each domain is counted once per response, even when an answer cites multiple URLs from that domain. Shares use all 375 responses as the denominator. Tied domains retain the stable aggregate order.

What changed since Q3?

The frozen panel cited 1,411 distinct domains in Q4, compared with 1,510 in the Q3 benchmark. Mean pairwise cited-domain overlap moved from 0.094 to 0.103. That is a small increase, not convergence: 65.5% of the domains in the combined engine top-25 lists were still exclusive to one engine's list. Provider identifiers stayed the same, but retrieval indexes can change, so the comparison is observational. These changes are observational evidence, not proof of a durable causal trend.

Which leading domains moved?

The table compares response-level citation share for selected domains in both quarters' top 100. A positive change means the domain appeared in a larger share of the same 375-response panel.

AI engines cited deep pages, not homepages

Only 1.3% of the 3,661 cited URLs were homepages. 81.1% were at least two path segments deep, up from 74.7% in Q3. Page-level monitoring is therefore the useful unit: a domain mention does not reveal which guide, comparison, documentation page, product page, or discussion supplied the answer.

Top 10 cited domains by engine

Every engine answered the same 75 prompts. The different leaders below show why a blended domain ranking cannot explain any single engine.

Do the five engines cite the same sources?

No. Foglift’s frozen Q4 panel found a mean pairwise Jaccard score of 0.103. Of the 84 domains in the five combined top-25 lists, 55 appeared in only one engine's top 25 and none appeared in all five. A citation win in one engine does not establish visibility in the other four.

How many engines share the same leading sources?

Interpretation limits

This is a fixed buyer-question panel, not a census of every AI answer. Rankings describe the 25 sampled verticals and the provider behavior observed during the collection window. Structural domain categories are a secondary annotation: 1,629 of 3,173 domain-citation occurrences were classified, so category-level conclusions should use that documented subset. The domain rankings, engine overlap, URL depth, and downloadable CSV do not depend on category completeness.

The operational conclusion is narrower. Citation sources differ by engine, move between quarters, and overwhelmingly resolve to specific pages. Foglift tracks all five engines, the cited pages behind each answer, and crawler plus referral evidence that connects visibility with actual site activity.