Skip to main content
USA-Based Digital Agency
AI Search Glossary

What Are AI Crawlers?

A new class of bots is reading your website — not to rank it, but to train models and answer questions live. Knowing which AI crawlers matter, and how to control them, is now part of technical SEO.

Quick Answer

AI crawlers are automated bots operated by AI companies to fetch web content for large language models — either to train future models or to retrieve live information when answering a user's question. Common examples include OpenAI's GPTBot and OAI-SearchBot, Anthropic's ClaudeBot, PerplexityBot, and Google-Extended. You control their access through your robots.txt file.

Training vs retrieval: the distinction that matters

Not all AI crawlers do the same job, and conflating them leads to bad decisions. There are broadly three purposes. Training crawlers (like GPTBot in its training role, or ClaudeBot) collect content that may be used to train future model versions. Live-retrieval crawlers (like OAI-SearchBot for ChatGPT search, or PerplexityBot) fetch pages in real time to answer a specific query — this is how your content gets cited in an answer right now. Training-control tokens like Google-Extended do not crawl at all; they are a signal that tells Google whether your already-crawled content may be used for Gemini/AI training.

The decision that trips people up: blocking training crawlers is a reasonable content-rights choice, but blocking live-retrieval crawlers can remove you from AI answers entirely. If PerplexityBot or ChatGPT's search crawler cannot fetch your page, you cannot be cited in their live responses. Many sites accidentally hurt their AI visibility by blocking bots they actually wanted answering questions about them.

Behavior and honesty of these bots vary. Reputable crawlers publish their user-agent strings and IP ranges and respect robots.txt; some scrapers ignore it. Verifying a bot against its published IP ranges (rather than trusting the user-agent alone) is the reliable way to confirm identity.

The block-too-much mistake

Blocking every AI bot to "protect" your content can silently remove you from ChatGPT search, Perplexity, and other AI answers — because their live-retrieval crawlers can no longer fetch you. Separate training bots (safe to block if you choose) from retrieval bots (block only if you accept losing AI citations).

How to control AI crawlers

Control happens mainly in robots.txt, using per-user-agent rules. You can allow live-retrieval bots (so you stay eligible for citations) while disallowing training bots (if you want your content excluded from model training) — the two are separate user agents, so you are not forced into all-or-nothing. Our free robots.txt generator includes templates for the common AI crawlers.

A few practical rules. Decide your goal first: maximum AI visibility means allowing retrieval bots; content-rights protection means disallowing training bots. Keep the rules current — AI companies add and rename crawlers regularly. And remember robots.txt is a request, not enforcement: well-behaved bots honor it, but it does not stop a determined scraper, for which server-level blocking is required.

Do not confuse AI crawlers with Googlebot. Googlebot still crawls for classic search and AI Overviews; blocking it removes you from Google entirely. AI-specific crawlers are additional bots with their own user agents — manage them deliberately rather than sweeping them in with a blanket rule.

Frequently Asked Questions

AI crawlers are bots run by AI companies to fetch web content for large language models, either to train future models or to retrieve live information when answering a user's question. Examples include OpenAI's GPTBot and OAI-SearchBot, Anthropic's ClaudeBot, PerplexityBot, and Google-Extended (a training-control token). You manage their access through your robots.txt file.
Both are operated by OpenAI but serve different purposes. GPTBot is primarily associated with collecting content that may be used to train models. OAI-SearchBot fetches pages in real time to answer queries in ChatGPT search. The practical implication: blocking GPTBot is a training/content-rights decision, while blocking OAI-SearchBot can remove you from ChatGPT's live, cited answers.
It depends on your goal. If you want maximum AI-search visibility, allow live-retrieval crawlers (OAI-SearchBot, PerplexityBot) so you can be cited in answers. If you want to keep your content out of model training on principle, you can disallow training crawlers (GPTBot, ClaudeBot) and set Google-Extended — these are separate user agents, so you don't have to choose all-or-nothing. Blocking retrieval bots means giving up AI citations.
Google-Extended is not a crawler — it is a robots.txt control token. It lets you tell Google whether content it has already crawled (via Googlebot) may be used to train and ground Google's AI products like Gemini. Blocking Google-Extended does not remove you from Google Search or AI Overviews; it only opts your content out of AI training use. This separation lets you stay in search while controlling training use.
Reputable, publicly-documented AI crawlers (GPTBot, ClaudeBot, PerplexityBot, and others) respect robots.txt directives. However, robots.txt is a request, not enforcement — it does not stop bad-actor scrapers that ignore it. For content you must protect from all bots, server-level or firewall blocking is required. Verifying a bot against its published IP ranges, rather than trusting the user-agent string, guards against impersonation.
Check your server access logs for known AI user agents (GPTBot, OAI-SearchBot, ClaudeBot, PerplexityBot, Google-Extended references) and verify them against the IP ranges each provider publishes. Some analytics and log-analysis tools now flag AI-crawler traffic specifically. Seeing retrieval bots fetch your pages is a positive signal — it means you are eligible to be cited in those engines' live answers.

Make sure AI engines can find and cite you

We audit crawler access, entity signals, and structured data so the right AI bots can read — and cite — your site. Start with a free growth plan.

Get Your Free Growth Plan
Get Free Growth Plan