In short. unavailable_after instructs Google to stop showing a page in search results after a specified date and time.

Definition: As of 17 October 2026, Google's robots meta tag specification defines unavailable_after as a page-level instruction to stop showing a page in search results after a specified date and time.

Key facts

Google's specification says Googlebot considerably reduces crawling of the URL after expiry.
Google's noindex documentation explains that crawlers need access to read meta tags and HTTP response headers.
Google's AI features documentation requires supporting links in AI Overviews and AI Mode to be indexed and eligible for Search with a snippet.

How is the expiry date written?

Google's specification gives this HTML example, placed in the page's <head>:

<meta name="robots" content="unavailable_after: 2020-09-21">

This is the documentation's historical example date. Accepted date formats include ISO 8601; an invalid or missing date makes the rule ineffective. Without the instruction, content has no default search expiry date.

The same specification permits an X-Robots-Tag HTTP response header. Its example includes a time zone:

X-Robots-Tag: unavailable_after: 25 Jun 2010 15:00:00 PST

How can implementation be checked?

Google's robots specification requires crawl access: blocking the URL in robots.txt, the file that controls crawler access, prevents Google from reading the instruction.

Google's noindex debugging guidance describes the URL Inspection tool in Search Console, Google's site monitoring service. It shows the HTML Googlebot receives while crawling a page. This provides a way to inspect a meta tag as received by the crawler. The same guidance allows a recrawl request through URL Inspection after a change. For noindex, the Page Indexing report also identifies pages where Googlebot extracts that rule.

Why does this matter for AI search?

Google's AI features guidance connects AI Overviews and AI Mode supporting links to Search eligibility. Applying a search expiry therefore concerns whether a page remains eligible to appear as a supporting link in these features. This follows from the eligibility requirement.

The guidance also names nosnippet, data-nosnippet, max-snippet and noindex as controls for information shown from pages in Search. When troubleshooting preview controls, Google recommends checking their visibility to Googlebot and allowing time for recrawling and processing.

FAQ

Does a future expiry date ensure my page appears before then?

No. Google's AI features documentation says meeting its requirements and policies still leaves crawling, indexing and serving subject to Google's systems.

Which rule removes a page without a scheduled expiry?

Google's noindex documentation describes noindex for preventing indexing. Once Googlebot reads the rule, Google drops the page from Search results, including when other sites link to it.

Sources

Check how a page reads to answer engines. Open the GEO score analyzer