Reddit’s share of citations in ChatGPT Search responses dropped sharply after OpenAI changed how the system expands and sources user queries. Data tracked by PromptWatch shows Reddit accounted for roughly 3.8% of all ChatGPT Search citations from July 18 through August 7. By August 14, that share had fallen to about 0.5%.
That represents an 86% relative decline, with the downturn beginning around August 8.
ChatGPT Search Citation Data Shows a Sharp Reddit Decline
PromptWatch’s data indicates that Reddit’s visibility within ChatGPT Search changed in a matter of days. The platform went from appearing in nearly 4% of cited responses during the measured July-to-August period to appearing in about one-half of 1% by August 14.
The change affects Reddit’s share of citations, not necessarily its overall traffic. A Reddit spokesperson said the platform remains among the most-cited domains in other reports. The spokesperson also said Reddit receives most of its visits from direct users and traditional search rather than large language models.
OpenAI’s Query Fanout Behavior May Be Behind the Shift
The decline appears connected to a change in ChatGPT’s “query fanout” behavior. This is the backend process that expands a single user question into several sub-queries, allowing the system to retrieve information from a wider range of sources.
According to PromptWatch data reported by Gizmodo, OpenAI began using a site: operator when conducting searches. Rather than starting with the open web, the system now appears to direct searches toward particular websites.
OpenAI did not publicly announce the change. Gizmodo contacted the company for comment but did not receive a response.
Why the Change Matters for Citation Visibility
The Reddit drop shows how a backend update can quickly change the sources that appear across a large number of AI search responses. When an AI system modifies the way it searches, expands questions, or selects domains, publishers may see their citation share move without warning.
Reddit has seen changes tied to OpenAI model adjustments before. Prior changes in 2025 affected referral traffic and correlated with shifts in Reddit’s stock price. The August 2026 decline, however, was described as much larger in scale.
The available information does not establish whether OpenAI intentionally reduced Reddit’s visibility or whether the change resulted from broader system optimization. That distinction remains unclear.
The Decline Appears Specific to OpenAI Systems
Reddit has not experienced the same dramatic fall in Google’s AI Overviews and AI Mode, according to the reported data. That suggests the shift is linked to OpenAI’s systems rather than a broad reduction in Reddit’s value as a source across AI search products.
For publishers and platforms, the difference matters. Citation visibility can vary by provider, even when the underlying content remains the same. A domain’s placement in one AI search system does not necessarily predict how it will appear in another.
Reddit Continues Its Own AI Content Experiments
At the same time that Reddit’s ChatGPT Search citation share declined, the company was expanding its own use of AI. A report from The Verge, cited by Gizmodo, said Reddit has started testing ways to turn posts and comments into short AI-generated videos and podcasts.
The feature was teased during a recent earnings call. It lets users switch between reading a post and listening to an AI-voiced version. The effort is part of Reddit’s broader attempt to keep users passively engaged with content.
Questions Around AI Search Source Selection
It is not known whether the reduction in Reddit citations reflects an intentional decision to deprioritize the domain. It could also be an unintended outcome of changes to how ChatGPT Search generates sub-queries and retrieves sources.
If the change was deliberate, it raises questions about how AI search providers choose the domains that their products favor. The episode also shows how rapidly citation patterns can change when those decisions happen through backend updates rather than public announcements.