Definition

Indexing is the process by which a search engine adds a page to its index, the database queried when a user runs a search. A page that is not indexed will never appear in results, no matter how good its content.

The three stages

• Discovery: the crawler finds the URL via a link, an XML sitemap or a manual submission
• Crawl: the crawler downloads the page (respecting robots.txt and the crawl budget)
• Indexing: Google decides whether to include the page in its index

Common causes of non-indexing

• noindex tag or robots.txt block
• Incorrect canonical tag
• Content considered low quality by Google
• Poor internal linking or orphan page
• HTTP status other than 200 (301, 404, 500)
• Weak EEAT signals on the site

Search Console diagnoses each case through its Pages report.