Noindex

Noindex is a directive that tells search engines to keep a page out of their index, so it will not appear in search results.

It is most commonly applied with a robots meta tag in the head of the page, or with an X-Robots-Tag HTTP header for non-HTML files like PDFs. Unlike a canonical tag, which is a consolidation hint Google may or may not honor, noindex is a directive Google respects. Once Google recrawls a page carrying it, the URL is dropped from the index.

<meta name="robots" content="noindex">

X-Robots-Tag: noindex

The key requirement is that Google must be able to crawl the page to see the tag. If you block the page in robots.txt, Googlebot never fetches it, never sees the noindex, and the URL can still end up indexed from external links with no description. To reliably remove a page, allow crawling and serve noindex; do not combine it with a robots.txt disallow. A common pairing is "noindex, follow," which keeps the page out of the index while still letting Google follow its links, though over time Google may treat long-term noindexed pages as effectively nofollow.

Typical uses include thin or duplicate pages, internal search results, staging URLs, thank-you pages, and faceted navigation that would otherwise cause index bloat. Audit noindex tags carefully, since an accidental noindex on important pages silently removes them from search.

Related: Indexing, Index bloat, Robots.txt reference, Indexation check