Indexability is whether a page can be discovered, crawled, and added to a search engine’s or AI system’s index. Pages blocked by robots.txt, marked noindex, or behind authentication are generally inaccessible to crawlers regardless of their content quality. Pages rendered only in client-side JavaScript may also be inaccessible to many AI crawlers, though Googlebot can render JavaScript.
A page that cannot be indexed cannot be cited. Indexability is the most fundamental technical requirement in AI SEO — it precedes all content and entity optimization. Common indexability failures include overly restrictive robots.txt files, reliance on JavaScript rendering, accidental noindex tags, and authentication walls on content that should be public.