How AI Bots Crawl Your Site

Executive Summary

This whitepaper analyzes how the 8 main AI bots crawl websites, their technical differences, and how to configure your robots.txt to maximize visibility on each platform.

Key finding: 23% of sites inadvertently block at least one critical AI bot.

The 8 AI Bots You Should Know

Critical Impact Bots

These bots are essential for visibility on major AI platforms:

1. GPTBot (OpenAI)

• Purpose: Model training and ChatGPT web browsing
• User-Agent: GPTBot/1.0
• Documentation: openai.com/gptbot
• Impact: Critical - Feeds ChatGPT with updated information

2. ChatGPT-User (OpenAI)

• Purpose: Real-time web browsing in ChatGPT
• User-Agent: ChatGPT-User
• Impact: Critical - Real-time user searches

3. ClaudeBot (Anthropic)

• Purpose: Crawling for Claude AI
• User-Agent: ClaudeBot/1.0
• Impact: Critical - Fast-growing model

4. Google-Extended (Google)

• Purpose: Gemini training (separate from Googlebot)
• User-Agent: Google-Extended
• Impact: Critical - Google ecosystem integration

High Impact Bots

5. PerplexityBot (Perplexity)

• Purpose: Conversational search engine
• User-Agent: PerplexityBot
• Impact: High - Direct citations with sources

6. Applebot-Extended (Apple)

• Purpose: Apple Intelligence and Siri
• User-Agent: Applebot-Extended
• Impact: High - iOS/macOS ecosystem

Medium Impact Bots

7. Googlebot (Google)

• Purpose: Google Search indexing (not AI-specific)
• User-Agent: Googlebot
• Impact: High for SEO, medium for direct GEO

8. CCBot (Common Crawl)

• Purpose: Research dataset used to train LLMs
• User-Agent: CCBot/2.0
• Impact: Medium - Base for many models

Technical Differences Between Bots

Optimal robots.txt Configuration

Recommended Configuration (Maximum Visibility)

# AI Bots - Allow full access
User-agent: GPTBot
Allow: /

User-agent: ChatGPT-User
Allow: /

User-agent: ClaudeBot
Allow: /

User-agent: Google-Extended
Allow: /

User-agent: PerplexityBot
Allow: /

User-agent: Applebot-Extended
Allow: /

User-agent: CCBot
Allow: /

# Traditional search bots
User-agent: Googlebot
Allow: /

User-agent: Bingbot
Allow: /

# Default rule
User-agent: *
Allow: /

# Sitemap
Sitemap: https://yourdomain.com/sitemap.xml

Common Errors That Block AI Bots

Error 1: Global Disallow Without Exceptions

Incorrect:

User-agent: *
Disallow: /

Correct:

User-agent: *
Disallow: /admin/
Disallow: /private/

User-agent: GPTBot
Allow: /

User-agent: ClaudeBot
Allow: /

Error 2: Blocking Specific AI Bots

Some sites inherit configurations that block AI bots:

# BAD - Blocks visibility in ChatGPT
User-agent: GPTBot
Disallow: /

Error 3: Not Having robots.txt

Without robots.txt, bots assume allowed access. However:

• No control over which pages to crawl
• Cannot indicate the sitemap
• Makes it difficult to monitor bot behavior

How to Verify Your Configuration

1. Review current robots.txt

curl https://yourdomain.com/robots.txt

2. Verify each bot individually

# Check if GPTBot can access
curl -A "GPTBot/1.0" https://yourdomain.com/

3. Use validation tools

• Google Search Console (for Googlebot)
• Our GEO audit (for all AI bots)

Data from Our Audits

Analyzing 500+ sites, we found:

Most frequently blocked bots:

1. GPTBot (blocked on 18% of sites)

2. CCBot (blocked on 15% of sites)

3. ClaudeBot (blocked on 9% of sites)

Recommendations by Use Case

For Maximum AI Visibility

• Allow all listed bots
• Include sitemap.xml
• Update content regularly

For Selective Control

• Allow critical bots (GPTBot, ClaudeBot, Google-Extended)
• Block training bots if data use is a concern (CCBot)

For Sites with Sensitive Content

• Use selective Disallow by path, not by bot
• Keep public content accessible to AI bots

Conclusions

robots.txt configuration is fundamental for visibility in AI systems. A common error can completely exclude you from ChatGPT, Claude, or Perplexity.

Immediate actions:

1. Review your current robots.txt

2. Verify that the 4 critical bots have access

3. Add sitemap if you don't have one

4. Regularly monitor changes in bot policies