How AI engines read the web
Answer engines reach the open web through dedicated crawlers. According to each provider's documentation, OpenAI's GPTBot, Anthropic's ClaudeBot, Google-Extended, and PerplexityBot all respect robots.txt directives.
These engines lean heavily on Schema.org structured data, the vocabulary backed by Google, Microsoft, Yahoo, and Yandex. GPTBot and Google-Extended both launched in 2023, and the share of research queries that begin inside an AI assistant has climbed every quarter since.
According to Google's own documentation, structured data helps machines understand what a page is about. Research on AI answer quality shows that pages with a clear heading hierarchy, direct definitions, named authorship, and outbound citations to authoritative sources are quoted far more often than thin or anonymous pages. The data shows the same pattern across all four major engines: clarity and provenance beat keyword density.