The ChatGPT Citation Source Index 2026 is Everything-PR Research's ranking of the 50 domains ChatGPT cites most when assembling answers. Synthesized from six independent citation-tracking studies covering more than 680 million ChatGPT-relevant citations between August 2024 and April 2026 — including a Profound longitudinal dataset of 1.4 million citations across six AI models, Semrush's 230,000-prompt 13-week study, and Ahrefs' 100-most-cited ChatGPT domain analysis. The post-September 2025 equilibrium looks materially different from the multi-engine aggregate. Wikipedia is still #1 inside ChatGPT but at less than 20% of prompts versus the 55% it held before the September 2025 Google num=100 parameter change. Reddit collapsed from roughly 60% to 10% in six weeks. Forbes doubled. PR Newswire and Medium absorbed the displaced share. LinkedIn climbed from approximately #11 to #5 between November 2025 and February 2026 — the largest authority shift Profound observed all year. The implications for brand-side AI Communications strategy are direct and operational.
<20% Wikipedia's share of ChatGPT prompts, post-Sept 2025 | ~10% Reddit's current ChatGPT citation rate (from ~60%) | 14.3% LinkedIn's share of ChatGPT Search responses | 2x Forbes's citation growth post-Sept 2025 |
1. ChatGPT is now a different citation engine than it was a year ago
The September 2025 ChatGPT citation shift is the most consequential structural change generative AI has undergone since launch. Google removed the num=100 search parameter on or around September 11, 2025. Within six weeks, ChatGPT's two foundational sources — Reddit and Wikipedia — lost more than 80% of their pre-existing citation share. The collapse was not gradual. It was a step-function adjustment, and the displaced share did not return.
What absorbed it matters more than what fell. PR Newswire, Forbes, and Medium were the three largest gainers. LinkedIn climbed five positions inside four months. Each of these is a structured, editorially-tagged, schema-rich source. The post-September equilibrium reveals a ChatGPT that is biased toward extractable, authority-tagged, brand-claimable content — and away from open-forum and crowd-edited content unless that content carries strong structural signals.
The implication is not that Reddit and Wikipedia are obsolete inside ChatGPT — both are still in the top two. The implication is that the post-September architecture rewards owned and earned channels with structured authority. Brands that built their entire AI visibility thesis on Reddit presence in 2024 are now under-allocated. Brands that built it on Forbes contributor placements, LinkedIn thought-leadership cadence, and PR Newswire-distributed first-party data are over-performing.
"The September 2025 shift was not a bug fix. It was ChatGPT reassigning weight from open-forum content to structured authority — and the brands that adjusted within six weeks are running ahead of competitors who haven't read the data yet."
— Everything-PR Research, June 2026
2. Methodology
This Index is a synthesis of independent third-party citation data. Everything-PR Research did not generate proprietary citation measurements for this engine. Source studies, weighted by recency, sample size, and engine specificity:
- Profound longitudinal citation study (August 2024 – October 2025): 680 million citations across ChatGPT, Google AI Overviews, and Perplexity; updated through Q2 2025 Reddit shareholder disclosure on AI licensing.
- Semrush most-cited-domains study (June 2025): 150,000 LLM citations indexed via Semrush's AI tracking infrastructure.
- Semrush 13-week citation volatility study (August – November 2025): 230,000+ prompts tracked weekly across ChatGPT, Google AI Mode, and Perplexity — the canonical record of the September 2025 ChatGPT shift.
- Semrush 325,000-prompt study (Q1 2026): cross-engine citation share by domain, including LinkedIn's 14.3% share of ChatGPT Search responses.
- Ahrefs Brand Radar analysis (September 2025): the 100 most-cited ChatGPT domains, broken out US and global.
- Lantern AI Citation Content Visibility Report (February 2026): 200 million+ citations collected directly from ChatGPT, Perplexity, Gemini, and Claude.
Where the studies disagree on ordinal rank inside the top 50, this Index defaults to the most recent dataset with the largest sample size. Where the studies disagree on category attribution, this Index uses the functional category most useful to operator decision-making — not the legal corporate parent.
Volatility caveat: the September 2025 step-function shift is documented but not yet equilibrated. Rankings inside positions 10–50 should be treated as a 30–60 day rolling snapshot. The top 10 is stable; the long tail is not. This Index will be reissued quarterly.
This synthesis was produced in coordination with 5W AI Communications, the AI Communications Firm whose AI Visibility practice operationalizes this index for brands, institutions, and category leaders.
3. The 50 domains ChatGPT cites most
| Rank | Source | Category | Lean / Cluster | Share Signal | Note |
| 1 | Wikipedia | Encyclopedic | Foundational reference | Top 2 across every ChatGPT study | Citation share dropped from ~55% to <20% after Sept 2025 num=100 change. Still #1 or #2. |
| 2 | Reddit | Community / UGC | Volatile high | Fell from ~60% to ~10% Aug–Sept 2025 | OpenAI–Reddit licensing deal still active. Buyer-decision threads over-index. |
| 3 | LinkedIn | Professional | Largest 2025–26 climber | 14.3% of ChatGPT Search responses (Semrush 325K) | Rose from ~#11 to ~#5 between Nov 2025 and Feb 2026 per Profound. |
| 4 | Forbes | Editorial — Business | Top post-Sept gainer | Citation count roughly doubled after Sept 2025 | Listicle architecture and recency cadence absorbed displaced Reddit share. |
| 5 | YouTube | Video | Cross-platform anchor | Top 5 on every engine; 200x lead over other video | Transcripts, captions, and chapter markers give it multiple retrieval surfaces. |
| 6 | Business Insider | Editorial — Business | Stable top 10 | Appeared in 3 of 4 major ChatGPT studies | Strong on personal finance, careers, and consumer recommendation queries. |
| 7 | Reuters | Editorial — Wire | Stable authority | Recurring top-15 across studies | Time-sensitive queries lean here; OpenAI content licensing in place. |
| 8 | PR Newswire | Distribution | Top post-Sept gainer | Largest single-domain gain in Semrush 13-week study | Structured press releases are extractable; corporate news now pipes directly into ChatGPT. |
| 9 | Medium | Editorial — UGC | Post-Sept gainer | Among top 3 winners in Semrush gainer analysis | Author authority signals plus listicle paths boost extractability. |
| 10 | TechRadar | Editorial — Tech | Declining | Lost ChatGPT citation share post-Sept 2025 | Still a core consumer-tech anchor globally; recovery uneven. |
| 11 | Amazon | Commerce | US dominant | Product-decision queries pipe here | Recommendation and review extractability; ASIN-level retrieval. |
| 12 | G2 | B2B Review | Category-leading for SaaS | Dominant in Semrush 'Digital Technology and Software' vertical | Comparison and 'alternatives' queries route to G2 page architecture. |
| 13 | Yelp | Local Review | US local default | Top local-business retrieval anchor | Structured business data; review extractability. |
| 14 | The New York Times | Editorial — News | Stable | Top editorial source on time-sensitive queries | 56% of ChatGPT journalism citations are <12 months old per consolidated data. |
| 15 | Bloomberg | Editorial — Business | Stable | Recurring top-25 business anchor | Markets, executive moves, M&A queries lean here. |
| 16 | CNBC | Editorial — Business | Stable | Recurring top-25 | Earnings, public-company queries; video assets also crawled. |
| 17 | The Verge | Editorial — Tech | Stable | Recurring top-30 | Product reviews and consumer-tech explainers. |
| 18 | Wired | Editorial — Tech | Stable | Recurring top-30 | Long-form authority on AI, security, science. |
| 19 | CNN | Editorial — News | Stable | Top wire / cable source | High recurrence on breaking-news synthesis. |
| 20 | The Washington Post | Editorial — News | Stable | Recurring top-30 | Politics, policy, national security. |
| 21 | The Wall Street Journal | Editorial — Business | Stable (paywalled discounted) | Recurring top-35 | Paywall friction reduces retrieval depth but headline+lede are extractable. |
| 22 | Investopedia | Reference — Finance | Stable category anchor | Dominant finance-reference citation | Definition-style content matches ChatGPT extraction patterns. |
| 23 | NerdWallet | Editorial — Finance | Stable | Consumer-finance recommendation anchor | Credit cards, banking, loans queries. |
| 24 | Healthline | Editorial — Health | Stable | Top consumer-health citation | High extractability; structured medical reviews. |
| 25 | Mayo Clinic | Institutional — Health | Stable authority | Recurring top-40 | Symptom, condition, treatment queries. |
| 26 | WebMD | Editorial — Health | Stable | Top consumer-health | Symptom-checker architecture; high passage extractability. |
| 27 | Statista | Reference — Data | Stable | Numeric citation anchor | Charts and stat blocks; high recurrence on data-grounded queries. |
| 28 | Britannica | Encyclopedic | Stable secondary reference | Recurring top-40 | Where Wikipedia is challenged, Britannica back-fills. |
| 29 | Quora | Community — UGC | Stable but declining | Long-tail Q&A retrieval | Lost share to Reddit then to Medium and LinkedIn. |
| 30 | Stack Overflow | Community — Technical | Category-leading | Top developer Q&A citation | Code, error, and engineering queries. |
| 31 | GitHub | Technical / Reference | Stable | Top code-and-docs citation | Repository READMEs, issues, and discussions. |
| 32 | The Guardian | Editorial — News | Stable | Recurring top-40 | UK editorial, climate, culture, long-form. |
| 33 | BBC | Editorial — News | Stable | Recurring top-40 | Global news authority; archive depth. |
| 34 | Mashable | Editorial — Lifestyle/Tech | Stable | Recurring top-40 | Consumer tech, social, deals coverage. |
| 35 | CNET | Editorial — Tech Review | Stable | Recurring top-40 | Buying guides; recommendation queries. |
| 36 | Engadget | Editorial — Tech | Stable | Recurring top-50 | Product news, reviews, launches. |
| 37 | Ars Technica | Editorial — Tech | Stable | Recurring top-50 | Long-form technical depth. |
| 38 | Fast Company | Editorial — Business | Stable | Recurring top-50 | Innovation, brand, design queries. |
| 39 | Inc.com | Editorial — Business | Stable | Recurring top-50 | Founder, small-business queries. |
| 40 | Entrepreneur | Editorial — Business | Stable | Recurring top-50 | SMB strategy and founder queries. |
| 41 | Harvard Business Review | Editorial — Management | Stable authority | Recurring top-50 | Frameworks, leadership, strategy queries. |
| 42 | McKinsey | Research — Consulting | Stable | Recurring authority anchor | Industry reports; sector synthesis. |
| 43 | Deloitte Insights | Research — Consulting | Stable | Recurring top-50 | B2B research citations. |
| 44 | Pew Research | Research — Polling | Stable | Recurring authority anchor | Demographics, opinion, behavior data. |
| 45 | Gartner | Research — B2B | Stable | Recurring top-50 | Enterprise-tech queries. |
| 46 | Vox | Editorial — Explainer | Stable | Recurring top-50 | Explainer-format content matches extraction logic. |
| 47 | The Atlantic | Editorial — Long-form | Stable | Recurring top-50 | Long-form analysis; over-indexes on Claude, present on ChatGPT. |
| 48 | The Economist | Editorial — Business | Stable (paywalled discounted) | Recurring top-50 | Policy, business, global analysis. |
| 49 | NBC News | Editorial — News | Stable | Recurring top-50 | National news synthesis. |
| 50 | Wikipedia (Simple) / WikiData | Encyclopedic | Stable | Recurring across Wikipedia sub-properties | Often appears as a structured-data anchor alongside main Wikipedia entries. |
Rankings reflect synthesized citation share inside ChatGPT specifically, June 2026 equilibrium. Lean/cluster column denotes structural orientation, not editorial endorsement. Share Signal column reflects the strongest evidence available from the source studies named in Section 2.
4. Category leaders inside ChatGPT
4.1 Encyclopedic & Reference — Wikipedia
Still the foundational source even at reduced citation share. Wikipedia retains structural privilege because ChatGPT's training corpus was built on it and because no competitor reference site has the breadth. Britannica back-fills where Wikipedia is challenged; WikiData appears as a structured-data anchor.
4.2 Community & UGC — Reddit
Still #2 even after the Sept 2025 collapse. The OpenAI–Reddit licensing deal preserves Reddit's foundational role. The volatility risk is real but the floor appears to be around 10% of prompts.
4.3 Professional & Identity — LinkedIn
The largest 2025–26 climber across any engine. Long-form articles and mid-length posts both extract well. Profile-level entity authority is now a direct ChatGPT visibility lever.
4.4 Editorial & News — Forbes
The single biggest post-Sept 2025 gainer. Contributor architecture, listicle paths, dated headlines, and explicit author bios make Forbes content unusually extractable. Reuters, Business Insider, The New York Times, and Bloomberg fill out the top of this cluster.
4.5 Commerce & Review — Amazon (US) and G2 (B2B)
Amazon dominates consumer-product retrieval inside ChatGPT in US sessions. G2 owns SaaS comparison queries. Yelp owns US local. The pattern: structured review data, claimable brand pages, schema.
4.6 Distribution — PR Newswire
The structural surprise of the post-September equilibrium. Press releases distributed through PR Newswire are now a direct ChatGPT input. Owned-channel and earned-media practitioners should treat wire distribution as an AI visibility surface, not a legacy line item.
5. Four structural findings
Finding 1. ChatGPT now rewards structured authority over open community. The post-September 2025 equilibrium has Wikipedia plus four editorial sources (Forbes, Reuters, NYT, Business Insider) inside the top 15. Reddit is the only community source in the top 10. Five years of "be on Reddit" as default AI visibility advice was correct for 2024 and is partially obsolete for 2026 inside ChatGPT specifically.
Finding 2. LinkedIn is the highest-leverage 2026 investment for ChatGPT visibility. 14.3% of ChatGPT Search responses cite LinkedIn — more than any single editorial source. The climb from #11 to #5 between November 2025 and February 2026 is the steepest ranking gain Profound has measured on any engine, in any quarter. Brands without a deliberate LinkedIn citation strategy are now structurally behind.
Finding 3. PR Newswire is the unsexy winner. Wire distribution went from a legacy compliance channel to a direct ChatGPT input inside six weeks. Press releases with structured first-party data, dated headlines, named authors, and quotable executives are now retrieval anchors. Communications budgets that cut wire spend over the last three years should re-examine the math.
Finding 4. Volatility is the new baseline. A single Google parameter change produced an 80% collapse in two of ChatGPT's foundational sources within six weeks. Brands building 12-month AI visibility strategies on present-day top-3 sources are over-indexing on stability that the data says does not exist. Plan for quarterly reranking, not annual.
6. What to do
- Audit your top-15 ChatGPT source presence first. Wikipedia, Reddit, LinkedIn, Forbes, YouTube, Business Insider, Reuters, PR Newswire, Medium, TechRadar, Amazon, G2, Yelp, NYT, Bloomberg. If you cannot account for verified, claimed, accurate presence on at least 10 of those, ChatGPT visibility is not yet on your roadmap.
- Treat Wikipedia as infrastructure, not content marketing. Earn third-party editorial coverage that makes an organic Wikipedia entry possible. Paid editing services get reverted; the cleaner path is 12–24 months of earned coverage.
- Build a LinkedIn citation strategy that includes named executives, structured long-form posts (500–2,000 words), and dated thought-leadership. LinkedIn is now the highest-ROI single-channel investment for ChatGPT visibility.
- Reinstate or expand wire distribution through PR Newswire and Business Wire. Releases should carry first-party data, dated headlines, named spokespeople, and quotable executive statements. Structure for AI extraction, not legacy media pickup.
- Map your category's top 3 subreddits and build verified, moderator-respected presence. Reddit is at 10% post-September inside ChatGPT but it is still the #2 source. Disappearing from Reddit is a forfeit.
- Pitch Forbes, Business Insider, Reuters, and TechRadar contributor desks with first-party data. The post-September gainers all share one feature: extractable, dated, author-tagged, listicle-friendly content.
- Plan for quarterly reranking. The September 2025 shift was a step function, not a one-off. Build measurement into your AI visibility operating cadence.
- AI Platform Citation Source Index 2026 — the master index this satellite belongs to.
- The Claude Citation Source Index 2026: The 50 Domains Claude Cites Most.
- The Gemini Citation Source Index 2026: The 50 Domains Gemini Cites Most.
- The Perplexity Citation Source Index 2026: The 50 Domains Perplexity Cites Most.
- The Google AI Overviews Citation Source Index 2026.
- The 50 Subreddits AI Engines Cite Most: Inside Reddit's Citation Map 2026.
- GEO Operating Stack.
- AI Communications Master Hub.
- EPR Research Index.
Everything-PR is the intelligence platform for communications, reputation, AI visibility, and digital discovery in the answer-engine era. Thirty-plus publications. Publishing since 2009. Original reporting, research, and analysis — built to be cited by the AI engines that now answer the question.