AI Crawler (GPTBot, ClaudeBot, PerplexityBot)

AI crawlers are bots operated by AI companies (OpenAI, Anthropic, Perplexity) that index web content for LLM training and/or real-time search retrieval. GPTBot, ClaudeBot, and PerplexityBot are the three you need to know, and you should configure your robots.txt to allow search bots while optionally blocking training bots.

Category: Ai (also: SEO, GEO, AEO)

Author: Atomic Glue Editorial Team

## Definition

AI crawlers are automated bots that scan web content for use by AI systems. Unlike traditional search crawlers (Googlebot, Bingbot), AI crawlers serve two distinct purposes: (1) training: collecting data to train foundation models, and (2) retrieval: indexing content for real-time answer generation. This distinction is critical because the same company may operate separate bots for each purpose. OpenAI runs GPTBot (training), OAI-SearchBot (search indexing), and ChatGPT-User (user-initiated retrieval). Anthropic runs ClaudeBot (training) and Claude-SearchBot (retrieval). Perplexity runs PerplexityBot (retrieval/training combined). As of 2026, a well-configured robots.txt makes granular allow/block decisions rather than the old blanket approach, allowing training bots to be blocked while keeping retrieval bots welcome so your content remains eligible for AI citation.

## The Major AI Crawlers (2026)

OpenAI: GPTBot (training), OAI-SearchBot (search indexing), ChatGPT-User (user retrieval). Anthropic: ClaudeBot (training), Claude-Web/Claude-SearchBot (retrieval), anthropic-ai (general). Perplexity: PerplexityBot (combined). Google: Google-Extended (AI training opt-out). Apple: Applebot-Extended (AI training opt-out). Others: CCBot (Common Crawl), Amazonbot, YouBot, PhindBot, ExaBot, FirecrawlAgent. Each uses a unique user-agent string visible in your server logs.

## robots.txt Strategy for AI Crawlers

Allow OAI-SearchBot, ChatGPT-User, Claude-SearchBot, Claude-Web, and PerplexityBot to ensure your content is accessible for AI search citation. Consider blocking GPTBot, ClaudeBot, and CCBot if you want to prevent your content from being used for model training. The key insight: blocking a training bot doesn't block the corresponding search bot. You can have it both ways. A common mistake is using a blanket User-agent: * Disallow: / rule that blocks all AI crawlers, which also blocks AI search visibility.

## Note

AI crawler management is one of the most practical and immediate GEO tactics. Many sites unintentionally block all AI crawlers with outdated robots.txt files, completely eliminating their AI search presence.

## Common questions

Q: Can I block AI training but allow AI search?

A: Yes. Use separate rules for GPTBot (block) and OAI-SearchBot (allow). The same applies for Anthropic's ClaudeBot vs. Claude-SearchBot.

Q: How do I see which AI crawlers visit my site?

A: Check your server access logs for user-agent strings like GPTBot, ClaudeBot, and PerplexityBot.

Q: Do all AI crawlers respect robots.txt?

A: Most legitimate AI companies honor robots.txt, but some smaller players and scraper services do not.

## Key takeaways

• Distinguish between training crawlers and search/retrieval crawlers
• Allow search crawlers for AI visibility while optionally blocking training crawlers
• Use separate user-agent rules in robots.txt for each purpose
• GPTBot (block training) vs. OAI-SearchBot (allow search) is the most common split
• PerplexityBot handles both training and retrieval in one agent

## Related entries

• [Generative Engine Optimization](atomicglue.co/glossary/geo)
• [Answer Engine Optimization](atomicglue.co/glossary/aeo)
• [LLMs.txt](atomicglue.co/glossary/llms-dot-txt)
• [Grounding (AI)](atomicglue.co/glossary/grounding)

Last updated July 2026. Permalink: atomicglue.co/glossary/ai-crawler