What Did Ahrefs Report About ChatGPT's Citations?
On October 12, 2026, Ahrefs published a study of how ChatGPT searches the web and which sites it cites. It combines two datasets. The first is 66.6 million free, logged-out GPT-5.6 Luna responses and 15 million fan-out queries (the background searches a model runs before it answers) from August and September 2026. The second is Ahrefs' Brand Radar panel of U.S. ChatGPT citations from March to September 2026, covering 2.4 million to 3.8 million answers a month (Ahrefs).
Ahrefs is a vendor that sells SEO and AI-visibility software, so its panel is a measurement product, not a record kept by OpenAI. We read the full Ahrefs post, written by Louise Linehan. The post does not quote OpenAI, we did not find an OpenAI statement on the pattern, and we did not repeat figures from other firms that Ahrefs cites unless Ahrefs states them itself.
How Much Did Reddit and Wikipedia Fall?
Ahrefs writes that in March, “about 1 in every 5 ChatGPT answers cited Reddit, but by late September it was about 1 in 43.” It puts Wikipedia at “1 in 7 answers to 1 in 35 over the same period,” and YouTube at “about 1 in 370 answers to 1 in 500” (Ahrefs). Ahrefs summarizes the Reddit change as a drop of 88% in six months. The post adds that these sites “are still among ChatGPT's most-cited domains.”
The decline is large, but the post gives it a hedge worth keeping. Prompts are added to Brand Radar over time, so a change in rank could reflect new questions. To test that, Ahrefs compared about 25,000 prompts that were among the 150,000 highest-volume prompts in both March and September. The post says: “Every site in the chart moved in the same direction on those identical prompts.”
| Domain | March | Late September | Source |
|---|---|---|---|
| About 1 in 5 answers | About 1 in 43 | Ahrefs | |
| Wikipedia | 1 in 7 | 1 in 35 | Ahrefs |
| YouTube | About 1 in 370 | 1 in 500 | Ahrefs |
| PubMed (rank among top 200 domains) | 64th | 4th | Ahrefs |
Which Sources Gained?
Ahrefs says the citations Reddit, Wikipedia and YouTube lost “went to research bodies, regulators, brands and hands-on testers, while explainer and aggregator sites fell.” Its health example is the clearest: PubMed rose from 64th to 4th among the 200 most-cited domains and the FDA entered at 8th, while WebMD and Verywell Health fell. Ahrefs' reading is that ChatGPT is “moving from sites that summarize information to the sources that produce it.” That reading is Ahrefs' interpretation of its panel, and the post shows rank changes, not the underlying citation counts for every site.
One group moved the other way. Among the 17 publishers and platforms Ahrefs says have licensing deals with OpenAI, partner titles in the top 200 cited domains more than doubled their combined citation share, from 7.5% in March to 15.8% in July, and held 12.5% in late September. Our guide to which publishers have AI licensing deals covers who those partners are.
What Is ChatGPT Looking Up Before It Answers?
Most answers involve no search. Ahrefs found that only 14.4% of the 66.6 million responses triggered a web search, and those that did ran about 1.6 fan-out queries on average. Ahrefs notes that it tracked “free, logged-out sessions, which search less than paid or reasoning models,” and that several other studies used commercial “best X” prompts that “naturally trigger brand lookups.”
Of about 15 million fan-outs, 6.8% used the site: operator to search one website, spread across about 116,000 domains. Among the roughly 160 most-searched sites, 75.9% of those searches pointed at a brand site.
% of site: searches
Share of site: searches among the roughly 160 most-searched sites in about 15 million fan-out queries from free, logged-out GPT-5.6 Luna responses, August and September 2026. The three rows do not sum to 100%; Ahrefs says government domains “also feature heavily” but gives no share for them. These are lookups ChatGPT ran, not the sites it cited.
The chart shows that when ChatGPT looked up a specific site, it overwhelmingly went to the company's own domain, with Reddit and Facebook together at 1.9%.
The wording of fan-outs moved the same way. Ahrefs reports that “official” rose from 10.1% to 13.1% of English fan-outs between August and September, and “price” from 6.04% to 8.88%, a relative rise of about 47%. In the 20,000-prompt test, 84.4% of factual questions about pricing, product features or company details cited at least one official website, and 63.4% of the citations on those questions were official. For comparison questions the figures were 68.3% and 46.4%.
Does This Mean Reddit and Wikipedia No Longer Matter?
No, and Ahrefs does not say so. It says the sites remain among the most-cited, and that ChatGPT “still fetches Reddit when it wants real users' opinions, despite citing it less often.” Ahrefs also points out that Reddit is the only OpenAI licensing partner among the 150 most site:-searched domains. For readers deciding where to invest, the supported conclusion is narrower: a plan that depends on one platform's share of citations rests on a number that moved a lot in six months. See our guides on whether Reddit threads show up in AI answers and which sources AI assistants cite.
What This Means for Anyone Buying a Placement
Three practical points follow from the data. Each is our recommendation, not a rule from OpenAI or Ahrefs.
- Your own pages carry weight. If lookups and citations lean toward official sites for facts, prices and company details, an accurate, crawlable page about your company is the first thing a model can cite. Ahrefs says that for many prompts, visibility depends on what ChatGPT “already knows about your brand, rather than what it can find.”
- Coverage is still read, but no outlet is guaranteed to be cited. Partner publications held a larger share of citations than in March, yet a paid article or sponsored post is advertising and is not a promise of citation, ranking or permanence. See how to check what AI says about your company.
- Track citations over time. A share that fell 88% in six months can also rise. Re-check the prompts that matter to you monthly, using your own logs and a documented prompt list.
Methodology and Limitations
Four limits apply. First, the data is Ahrefs' panel, and Ahrefs sells tools in this market. Second, the fan-out data covers one model (GPT-5.6 Luna) over two months, from free, logged-out sessions, and Ahrefs warns that OpenAI changes retrieval constantly. Third, citation rank is not traffic; the study does not report clicks or visits from citations. Fourth, we read Ahrefs' post and the OpenAI-partner and rank claims as Ahrefs reports them; we could not inspect the Brand Radar panel itself. Other studies listed in the post (from Nectiv, Peec and independent practitioners) used different prompts and models; Ahrefs says they agree on direction and that “The main difference is scale.” OpenAI is not quoted in the post, and we found no OpenAI statement on these figures.
Conclusion
Ahrefs' data says ChatGPT's citations moved toward originators of information between March and September 2026, and away from sites that summarize them. The finding is useful to a buyer for one reason: it argues for putting accurate facts on pages you control and for buying coverage because the audience reads it, not because a model will cite it. The share could reverse with the next model update.
Frequently Asked Questions
Is ChatGPT citing Reddit less in 2026?
According to Ahrefs' Brand Radar panel, yes. Reddit appeared in about 1 in 5 U.S. ChatGPT answers in March and about 1 in 43 by late September 2026. Ahrefs says Reddit remains among the most-cited domains.
Did Wikipedia also lose ChatGPT citations?
Ahrefs reports Wikipedia fell from 1 in 7 answers to 1 in 35 between March and late September 2026, and that it is still among ChatGPT's most-cited domains.
Which sites gained ChatGPT citations?
Ahrefs says research bodies, regulators, brands and hands-on testers gained. Its example is PubMed, which rose from 64th to 4th among the 200 most-cited domains, with the FDA entering at 8th.
How often does ChatGPT search the web?
In Ahrefs' sample of 66.6 million free, logged-out responses from August and September 2026, 14.4% triggered a web search. Paid and reasoning models may search more.
Does this tell me how many visits ChatGPT sends?
No. Ahrefs' study measures citations, the source links shown in answers, and does not report clicks or visits.
Can paying for an article make ChatGPT cite it?
No source we read says so. A paid article is advertising and should be labeled as sponsored content, and nothing in the Ahrefs study shows that payment buys citations.
Sources
This guide is built from one primary document, Ahrefs' October 12, 2026 study, read in full on October 14, 2026, plus Search Engine Journal's report on it for cross-checking. Ahrefs' figures are the vendor's own and were not independently verified. Everything under "What This Means" is house recommendation, not a platform rule. We did not test ChatGPT ourselves.
- vendor research Ahrefs, How ChatGPT Does Query Fan-Out (15 Million Queries Studied). Supports every figure above. Read October 14, 2026.
- trade press Search Engine Journal, ChatGPT's Most-Cited Sites Tilt Toward Primary Sources, Data Shows. Cross-check of dataset sizes and caveats. Read October 14, 2026.