Noindex is a crawler directive that is submitted to search engines, usually via a meta tag () or HTTP header. Its primary and unambiguous function is to instruct the crawler to crawl but not include the specific web page in the search engine’s main index. As a result, the page remains accessible to users, but is excluded from the search engine’s search results (SERP).
The conceptual meaning of noindex is related to index quality management and crawl budgeting. It is applied strategically to pages that are necessary for internal structure or user experience (e.g. policy pages, low-value archives, internal search results, thank you pages), but whose indexing would dilute the site’s authority or present low-quality content in the SERP.
In the context of SEO, the use of noindex demonstrates expertise in visibility control. It ensures that only the most relevant, original, and high-quality content competes for rankings, thus concentrating domain authority on key landing pages.