POLAND - 2025/03/07: In this photo illustration, a woman seen looking at a smartphone with a Reddit logo displayed in the background. (Photo Illustration by Mateusz Slodkowski/SOPA Images/LightRocket via Getty Images)SOPA Images/LightRocket via Getty ImagesReddit’s share of ChatGPT citations collapsed from 3.8% to 0.5% in days, after OpenAI changed how ChatGPT searches the web.Is ChatGPT leaving Reddit on read?Reddit's share of ChatGPT Search citations has plummeted to just 0.5% of responses, according to a Gizmodo report based on data from AI visibility platform PromptWatch. The drop was sudden. Reddit held a steady 3.8% average share of ChatGPT citations from July 18 through August 7 — one of the largest of any domain on the web. By August 14, it had fallen below 1%, and the August 14–17 average of 0.52% represents an 86% relative decline.For context on how far that is from Reddit's peak: as recently as April, Reddit was the single most-cited domain in ChatGPT Search, accounting for 4.14% of all citations.What Changed On August 8The slide traces back to a technical shift in how ChatGPT searches the web. On August 8, PromptWatch observed that ChatGPT Search began using the "site:" operator at scale — queries scoped to a specific domain jumped from 0.37% to 16.8% of all background searches within a single day, a roughly 46x increase. At the same time, the average number of searches ChatGPT runs per response nearly doubled, from about 1.08 to 1.83.In plain terms: instead of primarily searching the open web and seeing what comes back, ChatGPT now frequently goes directly to specific sites to pull information. Reddit's citation share slipped from the high 3% range to the mid-2% range that same day, then collapsed on August 14.MORE FOR YOUOpenAI has not explained the shift and did not respond to Gizmodo's request for comment. PromptWatch itself is careful to note that its data shows when each change happened, not why — and that a data-collection issue cannot be fully ruled out. A Reddit spokesperson told Gizmodo the platform remains one of the most-cited domains according to other reports, and noted that Reddit doesn't rely on LLMs for traffic, receiving most of its visits directly and through traditional search.Notably, the collapse appears specific to ChatGPT. Reddit's citation share in Google's AI Overviews declined only gradually, from about 2.5% in early July to roughly 2.1% in August, with a similar slow drift in Google's AI Mode.A Warning Shot For The AI Search IndustryThe episode lands as a case study in what marketers now call GEO — generative engine optimization, the practice of getting cited inside AI answers rather than ranked on a results page. A single unannounced backend change reshuffled the citation landscape for millions of queries, and publishers learned about it the way Reddit did: by watching the numbers drop.The marketing community took notice. Commenters on LinkedIn called AI search "a constant moving target" and urged brands to "stop building strategies around holes in the system."There is precedent for the anxiety. In September 2025, several AI-visibility trackers reported a similar collapse in Reddit's ChatGPT citations — and Reddit's stock moved with the coverage. That earlier drop was later attributed by some analysts to Google removing a search parameter that third-party data providers relied on, rather than to any deliberate decision. The lesson from both episodes is the same: visibility inside AI answers sits on infrastructure that platforms can rewire overnight, without notice.This week, Reddit joined the S&P 500, effective August 18. Shares jumped 13% on the inclusion news on August 14 — the very day the citation share cratered — before giving back about 8% on Monday as investors locked in gains. The stock traded around $153–156 midweek, well off its 52-week high of $282.95.The business, meanwhile, is hardly starving. Reddit's Q2 revenue grew 61% year over year to $805 million, though shares fell after the report on flat sequential U.S. user growth and continued search referral headwinds — a reminder that Reddit's relationship with the platforms that distribute its content remains its most-watched vulnerability.And Reddit is leaning further into AI itself, not away from it. Per The Verge, the company has begun experimenting with turning posts and comments into AI-generated short videos and podcasts, complete with a "Read/Play" toggle — part of a push, teased on its recent earnings call, to let people listen to posts in the background.Which leaves the two companies in a curious dance: OpenAI’s chatbot citations and Reddit’s work to sound more like a chatbot every day.