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Who Do AI Engines Cite?
the top citation sources for ChatGPT, Google, Perplexity, Gemini & Claude
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~40%
of all AI citations go to Reddit
(5W Index, 680M citations)
11%
domain overlap between ChatGPT & Perplexity citations — each engine is its own game
3–6
sources per AI answer vs ~10 in a SERP — a much smaller winners' circle
Google AI Overviews
mirrors the SERP… less every month
Top sources: YouTube (~30% of AIOs!), Wikipedia, Reddit, Quora
- Heavy bias to UGC + video — YouTube has a ~200x edge over any other video source
- Top-10 organic → AIO citation link is weakening: ~76% in 2025, under 40% by 2026
- Strong brand signals (branded search, mentions) matter more here than elsewhere
play: video + ranked page + entity-clean schema
ChatGPT
reference + community brain
Top sources: Wikipedia, Reddit, Forbes, G2, Medium
- Leans encyclopedic + discussion content; loves "best of" listicles & review hubs
- Cites brand-owned domains rarely (~0.6% of answers) — 3rd-party mentions do the work
- Most volatile engine: citation sources reshuffle in weeks, not years
play: get talked about on Reddit, G2, press & listicles
Perplexity
the academic + news nerd
Top sources: Reddit, LinkedIn, YouTube, NIH, Wikipedia
- Most generous brand citer (~13% of answers cite brands — 20x+ ChatGPT)
- Favors fresh news, studies, .gov/.edu & company pages over creator content
- LinkedIn company pages punch way above their weight here
play: publish original data, keep company pages sharp
Gemini / AI Mode
keeps it in the Google family
Top sources: YouTube, Google properties, Reddit, LinkedIn, Facebook
- Clear preference for Google-owned surfaces — Maps, YouTube, Business Profiles
- UGC domains gained most after the Sept 2025 ranking shakeups
- AI Mode & AI Overviews cite the same URLs only ~14% of the time — treat them separately
play: YouTube presence + fully built-out GBP
Claude
the careful librarian
Top sources: Wikipedia, Reddit, docs & reference sites, news wires
- Patterns track ChatGPT's reference-heavy profile in cross-engine studies
- Rewards semantically complete, well-structured documentation (think Zapier-style pages)
- Smaller search volume today, but included in every major 2026 citation index
play: deep, self-contained reference pages win
⭐ The cross-engine 5
cited (almost) everywhere
Reddit · Wikipedia · YouTube · LinkedIn · Forbes/news
- Top 15 domains absorb ~68% of the AI answer pipeline
- Journalism = ~27% of all citations, ~49% on time-sensitive queries
- But no single domain exceeds ~5% on any one platform — it's a long tail with fat outliers
presence on 4+ trusted platforms ≈ 2.8x more ChatGPT appearances
Vertical winners differ
| SaaS / software | G2, Reddit, Capterra, vendor docs |
| Health | NIH, .gov, major hospital systems |
| Finance | Bloomberg, SEC, Investopedia, NerdWallet |
| Local / services | GBP, Yelp, Reddit threads, local news |
| Media / tech | NYT, Reuters, The Verge, TechRadar |
find YOUR vertical's citation set before writing anything
What actually gets a page cited 📌
- Quotable data points, definitions & extractable tables beat raw domain authority
- ~44% of LLM citations come from the first 30% of the text — front-load the answer
- Depth, readability & freshness outrank backlinks as citation signals
- Structured content (headings, lists, FAQ) is the most effective format
- Optimized review profiles (Trustpilot, G2) drive co-mentions when buyers ask about competitors
The borrowed-authority playbook
- Map your vertical's citation set — run your money questions through each engine, log every cited domain
- Win your own pages — answer-first, structured, front-loaded, fresh (see the AEO process ↓)
- Get onto the cited 3rd parties — Reddit presence, listicle inclusions, G2/review profiles, PR & news wires, LinkedIn company page, YouTube
- Track citation share monthly — same question set, every engine, trended; volatility is measured in weeks
THE BIG IDEA
You can't rank your way into AI answers from your domain alone.
Be present where the engines already look — and make every page of yours the easiest thing in the index to quote.
Synthesized from 2025–2026 citation studies: 5W AI Platform Citation Source Index (680M citations), Profound, Semrush (325K prompts), Peec AI (30M sources), Lantern (200M citations), Ahrefs & Seer Interactive. Shares vary by study & month — treat as direction, not gospel.