What is AI Crawler?
An AI crawler is an automated bot that AI providers use to sweep the open web - to index content, retrieve it in real time for answers, or gather training data. Well-known ones are GPTBot, OAI-SearchBot and ChatGPT-User (OpenAI), ClaudeBot and Claude-SearchBot (Anthropic), PerplexityBot, and Google-Extended for Gemini.
These bots are governed through the robots.txt at the domain root, where you set per user-agent which areas a crawler may read. Many sites block AI crawlers wholesale - partly over copyright worries, partly out of old habit. In doing so they shut out exactly the systems that now answer a growing share of research.
The distinction by purpose matters: a training crawler such as GPTBot feeds models, while a retrieval crawler such as OAI-SearchBot or PerplexityBot fetches content live for a specific answer. If you want to be cited in AI answers, you should at least let the retrieval bots in - otherwise the page simply does not exist for AI search.
Why does AI Crawler matter?
Block AI crawlers in robots.txt and no language model can cite you - however good your content is. Since traffic from AI answers more than tripled between 2024 and 2025 (Similarweb), a blanket block is now an expensive reflex.
AI Crawler in practice
- 01In robots.txt you allow retrieval bots deliberately: `User-agent: OAI-SearchBot` and `User-agent: PerplexityBot` with `Allow: /`.
- 02Google-Extended controls only Gemini and AI use - the normal Googlebot for classic ranking is unaffected.
- 03An accidental `Disallow: /` for GPTBot makes your content invisible to ChatGPT's web search without changing your Google ranking.
