Everything-PR, the media property covering communications, reputation and AI visibility, has published the AI Platform Citation Source Index 2026 — a research index ranking the 50 websites most cited by generative AI answer engines.
The index synthesizes verified data from six of the largest published studies of AI citation behavior conducted between August 2024 and April 2026, together covering more than 680 million individual citations across ChatGPT, Claude, Perplexity, Gemini and Google AI Overviews.
The findings show that AI answers draw from a narrow, concentrated set of sources. The top 15 domains capture roughly 68 percent of all AI citation share. Reddit is the single most-cited source, appearing in approximately 40 percent of generative answers. Journalistic content accounts for 27 percent of all AI citations, rising to 49 percent for time-sensitive queries.
The research also documents severe volatility. In one six-week window in 2025, a leading source’s citation share on a major platform fell by roughly 50 points following a single upstream change to search parameters — evidence that AI citation patterns can be repriced within weeks.
“The modern equivalent of ‘what does Google rank first’ is ‘what does an AI engine cite first,'” said Ronn Torossian, Publisher of Everything-PR. “That question has an answer — and the answer is neither open, neutral, nor stable. Any organization building visibility in 2026 without knowing which sources AI engines cite, and in what order, is working from a map that is already out of date.”
The full index ranks all 50 sources across six functional categories — community, encyclopedic, professional, video, editorial and commerce — and includes a platform-by-platform breakdown of how each answer engine cites the web differently. Everything-PR Research will revise the index quarterly.
The complete AI Platform Citation Source Index 2026 is available at https://everything-pr.com/ai-platform-citation-source-index-2026/.
About Everything-PR
Everything-PR covers communications, reputation, AI visibility, public affairs, media systems, and digital discovery in the answer-engine era. Publishing since 2009. 31 verticals. Original reporting, research, and analysis. Every page reported, sourced, and built to be cited.