unavailable_after Meta Tag Example
My horn's summons, thawed out by the kitchen fire, called up the regiment for a war that had ended two winters before.
The short answer
- What it is
- unavailable_after is a robots rule that tells search engines to stop showing a page after a set date. The issue is a date that has already passed.
- Why it matters
- A past date can drop a live page from search with no visible sign on the page. It usually means an old event or campaign tag was reused and left in place.
- How a crawler should report it
- A crawler should show a warning that names the parsed date, the source as meta tag or header, and how long ago the date passed. A future date should raise no warning.
- Live examples
/lab/unavailable-after-past/(positive)/lab/unavailable-after-past/near-miss/(near miss)
Setting an expiry date for a page in search results
The unavailable_after rule gives a page an end date in search. It can sit in a meta tag, as in <meta name="robots" content="unavailable_after: 2030-12-31">. It can also go in an X-Robots-Tag header. Google accepts widely used date formats, including ISO 8601, RFC 822, and RFC 850. If the date cannot be read, Google ignores the rule. Other engines may not support it, so check their docs.
This rule is a good fit for pages with a known end, such as an event, a sale, or a job post. It goes wrong when a date stays in a template after the event ends. A page may be reused for next year, or a shared header may keep an old date. A date typed in the wrong format can also be read in a way that you did not expect.
Browsers ignore the rule, and the page stays live for visitors. Search engines read the date when they crawl the page. Once the date has passed, Google stops showing the URL in results, though this does not happen at the exact minute. If the page has already been crawled with a past date, it can act much like noindex. The page remains on your server, so people with the link can still reach it.
To detect the issue, look for unavailable_after in both the meta robots tag and the response headers. Parse the date and compare it with today. Flag any date in the past. Also watch for dates that are close, so you can decide in time. To fix a live page, remove the rule or set a later date, and then ask for a recrawl. If the page really has expired, remove it or redirect it to a useful page.