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- კომენტარები არ არის
- July 16, 2026
Table of Contents
In September 2025, ChatGPT unexpectedly and significantly reshaped the landscape of Cited Domains in AI by reducing citations of Reddit and Wikipedia—two of the sources it had previously referenced most frequently.
Reddit and Wikipedia
SEO specialists quickly linked this shift to changes in how Google delivers search results. But was that really the cause?
We analyzed prompt data across multiple LLM platforms to understand exactly what happened. Before presenting the research findings, let us first examine the widely discussed theory and why it may not tell the full story.
The Widely Discussed Theory Behind the Decline in Reddit and Wikipedia Citations
In mid-September 2025, Google removed the num=100 search parameter, which had allowed tools to access results beyond the first page, including positions 21–100.
If ChatGPT had been using this parameter to find Reddit and Wikipedia results ranking in deeper positions, its removal could explain the sharp decline in citations. Lily Ray, Vice President of SEO Strategy and Research at Amsive, raised this possibility on X, formerly Twitter.
Lily Ray quote — Portali
However, Sergey Rogulin, Head of Organic and AI Visibility at Semrush, does not fully agree with this explanation.
Personally, I do not believe that removing the num=100 parameter was the main reason — or at least not the only one. Correlation does not always imply causation.
Sergey Rogulin, Head of Organic and AI Visibility at Semrush
According to him, Semrush Organic Research data shows that Reddit ranks for approximately 263 million keywords in Google, and only around 90 million, or 34%, rank in positions 21–100.
Semrush Analytics
This does not align with the scale of the decline in Reddit citations observed in ChatGPT.
Sergey suggests that the more likely explanation is an attempt to reduce overreliance on specific domains, making AI systems less biased toward particular websites and more resistant to manipulation.
What is clear is that this event demonstrated just how volatile Cited Domains in AI and overall AI visibility can be.
Key Findings
- Reddit and LinkedIn remain among the most frequently cited domains in ChatGPT, Google AI Mode, and Perplexity.
- The sharpest changes occurred in ChatGPT, where Reddit and Wikipedia citations dropped significantly in mid-September.
- Despite the decline, Reddit and Wikipedia remain two of ChatGPT’s most frequently cited sources.
- Google AI Mode appears to favor domains owned by or closely associated with Google.
Research Methodology
To better understand changes in AI visibility, we analyzed:
- More than 230,000 prompts.
- Three LLM platforms: ChatGPT Search, Google AI Mode, and Perplexity.
- Thirteen weeks of data, from July 14 to October 12, 2025.
- The 25 most frequently cited domains on each platform every week.
- More than 100 million AI citations in total.
The Most Frequently Cited Domains Across AI Platforms
Despite the sharp decline in ChatGPT, Reddit and Wikipedia were still among the most frequently cited domains across all platforms by October 2025.
Website Rankings
Reddit appeared in approximately 60% of ChatGPT responses at the beginning of August, but by mid-September, that figure had fallen to around 10%.
At the same time, Reddit citation rates remained much more stable in Google AI Mode and Perplexity.
Wikipedia
Wikipedia citations in ChatGPT fell from approximately 55% to below 20%.
In AI Mode, Wikipedia remained stable at around 3%, while in Perplexity it stayed near 0.8%. This suggests that the change was not systematic across every LLM platform.
LinkedIn citations showed an upward trend across all platforms.
LinkedIn — and partly Forbes — may have filled some of the space lost by Reddit and Wikipedia.
Forbes
After September, Forbes doubled the number of ChatGPT responses in which it was cited. Growth was also recorded in AI Mode and Perplexity, although on a smaller scale.
Winners and Losers After the September Change
We then examined which websites experienced the largest positive or negative changes in citation frequency after Google removed the num=100 parameter, around September 11, 2025.
In ChatGPT, the biggest winners were:
- PR Newswire
- Forbes
- Medium
The biggest losers were:
- Wikipedia
In Google AI Mode, the most significant changes affected user-generated content domains.
Changes on Perplexity were more limited, although Reddit also showed a negative trend there.
The Most Frequently Cited Domains on Individual AI Platforms
Charts tracking the five most frequently cited domains across all three LLMs clearly show how the decline of Reddit and Wikipedia affected ChatGPT.
ChatGPT
Before September, Wikipedia and Reddit were cited approximately five times more often in ChatGPT responses than the next most frequently cited domains.
After mid-September, the two dominant sources moved closer to competitors such as Medium, Forbes, and LinkedIn.
Below is a more detailed comparison of the period before Google removed the parameter and the five weeks following the change.
ChatGPT Citation Trends
Reddit and Wikipedia experienced sharp declines before stabilizing and regaining the lead with a more balanced share of citations.
Google AI Mode
Google AI Mode
Over the quarter, AI Mode displayed a much more balanced mix of cited domains. Its most frequently cited sources included:
- YouTube
- Google Blog
All of these domains are either owned by Google or have a close partnership with it.
Although Reddit citations increased toward the end of August and then declined again, the overall composition of the leading domains remained more stable throughout the research period than it did in ChatGPT.
Compared with ChatGPT, Google AI Mode cited Wikipedia much less frequently. Wikipedia appeared in approximately 2% of AI Mode responses.
Why This Matters for Marketers
The data does not provide a definitive answer as to why these changes occurred.
However, it reveals one important fact: AI citation patterns can change very quickly, and these changes do not affect every platform in the same way.
For marketers, this means:
- AI visibility should be monitored in the same way as SERPs.
- Changes in citation patterns indicate which sources AI systems currently trust.
What Should You Do Now?
Semrush
General data is useful, but the real value begins when you analyze your own niche.
- Which domains dominate AI citations in your industry?
- Which platforms are gaining influence, and which are losing it?
- Where does your brand appear, and where is it missing?
Identify the sources that AI systems trust in your field and build relationships with them. This can help strengthen your own authority and increase the likelihood that your brand will be cited in AI-generated answers.
