What is noindex?
noindex is a directive in a page or an HTTP response that tells a supporting search engine not to include that page in its search index.
It concerns whether the retrieved page can appear in search results. It is separate from the robots.txt rules that tell a crawler whether it may fetch a path.
Why blocking a crawler can prevent it from seeing noindex
Google needs to retrieve the relevant instruction. If robots.txt prevents Google from fetching the page, Google may not see a noindex directive inside it.
When a page remains visible unexpectedly, check which instruction is actually reachable. Do not assume that placing a directive in a local file establishes that a crawler received it.
How does it relate to Google's AI search features?
The cited Google guidance treats AI Overviews and AI Mode as Search features. Existing controls, including noindex and snippet directives, apply within the scope described by that guidance.
Those controls have different purposes. A snippet restriction and an indexing restriction should not be treated as interchangeable, and neither provides authentication for private content.
Sources and scope
- Google Search Central: block indexing with noindex
- Google Search Central: AI features and your website
Source-language entry records a source check on 2026-09-26. This adaptation preserves that provenance and does not represent a new audit of the cited pages.