Most-cited domains by engine — top 5 sources per AI platform

Each AI engine trusts a different top-source mix. From Peec’s 30-million-source US analysis (full study, Mar 2026), the top 5 cited domains per platform:

Platform	Top 5 sources
Google AI Mode	YouTube, Reddit, Facebook, LinkedIn, Yelp
AI Overviews	YouTube, Reddit, Facebook, LinkedIn, Medium
Gemini	Reddit, YouTube, Wikipedia, Medium, PCMag / Forbes
Perplexity	Reddit, YouTube, LinkedIn, Wikipedia, G2
ChatGPT	Wikipedia, Reddit, Forbes, Techradar, LinkedIn

Patterns worth acting on (Mar 2026 data):

Reddit and YouTube appear in all five platforms’ top 5 — the only universal signals.
Google’s AI Mode and AI Overviews favor social content (Facebook, Yelp); ChatGPT leans editorial (Forbes, Techradar).
Wikipedia is strong for ChatGPT and Perplexity but absent from Google’s top 5.
G2 appears only for Perplexity — relevant for B2B teams.
Facebook blocks Perplexity’s bots entirely (robots.txt), so Facebook presence is a dead end for that channel; it still matters as diversification on Google’s surfaces.

Overall cross-engine ranking: Most-cited domains in AI search. Source: Top domains cited by AI search: Analysis based on 30M sources, Peec (Tomek Rudzki), Mar 2026.