# 4.5 Weeks: How Quickly an AI Forgets You Again

> A large study shows AI forgets unchanged content after 4.5 weeks on average. Why staying current matters and what you can do about it.

On average, an AI answer engine takes just 4.5 weeks to "forget" unchanged content on a single website and start citing it less often, or not at all. That's the median citation half-life measured by a large Scrunch and Stacker study in early 2026 — more than three million citation events across eight industries and six AI platforms, tracked over 26 weeks.

Think of an AI as a memory that's constantly being re-fed. What you "told" it a few weeks ago fades — not because it was wrong, but because fresher stories simply crowd it out.

## Why an AI "forgets" anything at all

An AI doesn't forget in a technical sense — it constantly re-weighs which source currently counts as up to date and reliable, and older, unchanged pages automatically slip down the list. How fast that happens differs from system to system. ChatGPT is the quickest, on average after around 3.4 weeks. Google's AI surfaces take a bit longer, roughly 4.3 to 4.8 weeks. Perplexity holds onto old sources the longest, on average 5.7 to 5.8 weeks.

## The simple lever against it: staying current

The most effective lever against being forgotten is refreshingly simple: according to the same study, content updated within the last 30 days gets around 3.2 times more AI citations than older, untouched pages. A website that's never touched is like a shop window that hasn't been redecorated in months — passers-by eventually stop looking. An AI does much the same thing: it favours the source that's visibly being kept up.

## What this means for your business

For you, that means becoming AI-readable once isn't enough if the content then sits untouched for months. A simple example: if a business changes its opening hours in autumn but the website still shows the summer hours, an AI is likely to pick up the outdated figure — or simply leave the business out of the next answer, because it favours a more current source.

Keeping things current takes the least effort when these facts are maintained in a single place and update everywhere automatically, instead of having to be corrected by hand in five different spots. That way, "updating regularly" stays a matter of minutes, not a project of its own.

For a full overview of AI visibility in South Tyrol and the DACH region, read the [guide to AI visibility](https://btlabs.dev/en/posts/ai-visibility-south-tyrol-dach).

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Source: https://btlabs.dev/en/posts/ai-citation-half-life-forgets-you
Last-Modified: 2026-08-01T04:29:30.036Z
Languages: [de](https://btlabs.dev/llms/de/posts/zitations-halbwertszeit-ki-vergisst) · [it](https://btlabs.dev/llms/it/posts/emivita-citazione-ia-dimentica)
See also: [llms.txt](https://btlabs.dev/llms.txt) · [ai.txt (Policy)](https://btlabs.dev/ai.txt) · [identity.json](https://btlabs.dev/identity.json)