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.
From the journal
- AI Visibility Check: What 20 Checks Reveal About Your WebsiteChatGPT, Perplexity and Google AI Overviews are becoming the first port of call for more and more people - but whether your website shows up there is decided at very concrete, testable points. Our free AI visibility check tests 20 of them. Here is what the four categories mean and why they decide your visibility.
- GEO not SEO: how your brand shows up in ChatGPT and PerplexityMore and more people research in ChatGPT, Perplexity and Google AI instead of classic search. If you are not named as a source there, you are invisible to a growing audience - no matter how well your website ranks. GEO is the discipline that changes this: becoming visible in the AI answer, not just the search result. Here is how it works.
