Between 18 July and 7 August, reddit.com held a steady 3.83% of ChatGPT Search citations. Between 14 and 17 August it averaged 0.52%. That is an 86.4% relative decline in four days.
No announcement, no policy post, no deprecation notice. Search Engine Journal's coverage is built around the fact that the drop still is not fully explained, and that is the most useful part of the story.
The obvious suspect does not quite hold. ChatGPT Search changed its query fan-out behaviour on 8 August, and its use of the site: operator jumped from around 0.4% to nearly 17% of fan-out queries that day, then kept climbing. But the main decline started on 14 August. The timing is close enough to be suggestive and far enough apart that nobody can claim certainty.
It was also specific to one engine. Promptwatch found no comparable one-day fall in Google's AI products. Reddit's share of citations in Google AI Overviews drifted from about 2.5% in early July to roughly 2.1% in August. That is a slope, not a cliff.
Sources: https://www.forbes.com/sites/gabrielalinzainescu/2026/08/20/reddit-nearly-vanishes-from-chatgpt-citations-after-openai-search-change/, corroborated by https://searchengineland.com/reddit-chatgpt-search-citations-fall-report-485473 and https://www.searchenginejournal.com/why-reddits-chatgpt-citation-drop-isnt-fully-explained/586479/
What this means if you own a website
An AI visibility number is a reading, not a rank.
Search positions move slowly, and usually for reasons you can reconstruct afterwards. Citation share in an answer engine can lose most of its value in under a week, from a retrieval change that was never published, on one engine, while the others carry on unchanged. Reddit is among the most cited domains on the internet. It did not get advance notice either.
So the number only means something with its conditions attached: the date, the engine, the questions asked, and the denominator.
We publish our own method at https://reidify.design/research/measuring-ai-visibility, including the run where we scored ourselves 78% and the corrected run that scored 25%. That page argues quarterly testing is enough for a small business, and this episode does not change it. Chasing a weekly citation number is not a business activity.
What it does change is how much weight one reading can carry. It is a reading of a system that moves on its own, so it belongs in a record with a date on it rather than on a slide as a score.
The failure mode to avoid is the number that gets sold. "Your AI visibility is 62%" invites a founder to hear a property of their website. It is not. It is a property of their website and one engine's retrieval behaviour on one day, and only the first of those is theirs to fix.
If you measure, keep the dates and keep the misses. The misses are what tell you whether the number moved because you did something, or because someone else did.
