Citation Decay
Citation decay is the drop in how often AI answers cite a page after it has been cited. Profound, which tracks AI answers, added a Citation Decay view in September 2026. It follows each page's share of citations from its peak and counts the days until that share falls to half and stays there: the page's half-life.
Source: Profound, Introducing Citation Decay in Profound (Joey Adelman and Matthew Huo, September 29, 2026), checked October 29, 2026
What Citation Decay means for your business
In a study published September 30, 2026, covering 883,000 pages, Profound, which sells a tracking tool, found the median page lost half its citation share within 11 days of its peak. Ahrefs, which sells one too, tracked cited websites day by day for 20 days and reported on October 29, 2026 that about three in four of the citations that dropped out came back before the study ended.
So a site that dropped out of an answer this week may be back next week. We'd judge decay over weeks, not from one check. When a page stays gone, we'd read it the way a buyer would and ask whether it still answers the question well. Our content decay entry covers the slow slide in Google clicks, which is a separate measure.
You may also see citation velocity, for the same curve going up: how fast a page picks up citations. Profound calls that climb the rise, the days from a page's first citation to its peak.
If one bad week in an AI tool has you worried, how we count across many runs explains why a monthly rate tells you more than a single check.
Sources: Profound, The half-life of an AI citation is 11 days (September 30, 2026); Ahrefs, How Stable Are AI Citations? 10 Things We Learned Tracking 37,500 Citations (October 29, 2026), checked October 29, 2026
Last reviewed October 29, 2026. All terms
How AI answers it today
On October 29, 2026, Google's AI Overview gave a definition close to Profound's and cited AI tracking vendors' glossaries, Similarweb and Profound's own posts. ChatGPT treated it as old references going stale or offline, with no mention of AI answers and no sources cited.
Our run through ChatGPT and Google's AI Overview, October 29, 2026. A sample, not what every buyer sees.
Related terms in measurement
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