GPTBot, ClaudeBot, PerplexityBot: The AI Crawler Guide

Understanding AI Crawlers

AI crawlers are web bots that collect content for training language models and powering real-time AI features. Unlike search engine crawlers that index pages for search results, AI crawlers gather data to improve AI assistants' knowledge and capabilities.

If you want AI assistants to cite your website, you need to allow these crawlers access. This guide covers all major AI crawlers and how to configure your site for them.

Major AI Crawlers

GPTBot (OpenAI)

User-Agent

GPTBot

Full User-Agent String

Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; GPTBot/1.0; +https://openai.com/gptbot)

Purpose

Crawls websites to improve ChatGPT and other OpenAI models. Used for training data and potentially real-time features.

Documentation

openai.com/gptbot

ChatGPT-User (OpenAI)

User-Agent

ChatGPT-User

Purpose

Used when ChatGPT users enable browsing to fetch live web content. This is different from GPTBot—it's for real-time lookups, not training.

ClaudeBot (Anthropic)

User-Agent

ClaudeBot or anthropic-ai

Full User-Agent String

ClaudeBot/1.0; +https://www.anthropic.com/claude

Purpose

Crawls for Anthropic's Claude AI training and improvement.

PerplexityBot

User-Agent

PerplexityBot

Purpose

Powers Perplexity AI's real-time search and answer engine. Perplexity actively cites sources with links, making this especially valuable.

Google-Extended (Google)

User-Agent

Google-Extended

Purpose

Used by Google for Bard/Gemini AI training. Separate from Googlebot (search indexing).

CCBot (Common Crawl)

User-Agent

CCBot

Purpose

Common Crawl is a nonprofit that creates open web archives. Many AI models use Common Crawl data for training, including early GPT models.

robots.txt Configuration

To allow AI crawlers, add explicit rules to your robots.txt file:

Allow All AI Crawlers (Recommended)

# AI Crawlers - Allow for LLM visibility
User-agent: GPTBot
Allow: /

User-agent: ChatGPT-User
Allow: /

User-agent: ClaudeBot
Allow: /

User-agent: anthropic-ai
Allow: /

User-agent: PerplexityBot
Allow: /

User-agent: Google-Extended
Allow: /

User-agent: CCBot
Allow: /

User-agent: Bytespider
Allow: /

Block Specific Sections

If you want AI access but need to protect certain areas:

User-agent: GPTBot
Allow: /
Disallow: /admin/
Disallow: /private/
Disallow: /api/

Note: Many hosting platforms and CMS systems block AI crawlers by default. Check your robots.txt to ensure you haven't inadvertently blocked them.

Complete robots.txt Example

Here's a full robots.txt optimized for AI visibility:

# Standard crawlers
User-agent: *
Allow: /

# AI Crawlers - Explicitly allowed
User-agent: GPTBot
Allow: /

User-agent: ChatGPT-User
Allow: /

User-agent: ClaudeBot
Allow: /

User-agent: anthropic-ai
Allow: /

User-agent: PerplexityBot
Allow: /

User-agent: Google-Extended
Allow: /

User-agent: CCBot
Allow: /

User-agent: Bytespider
Allow: /

# Sitemap
Sitemap: https://www.yoursite.com/sitemap.xml

# LLM Context Files
# See https://llmstxt.org for specification

Additional AI Crawlers

Other AI-related crawlers you may encounter:

Bytespider: ByteDance (TikTok parent company) crawler for AI training
FacebookBot: Meta's crawler, potentially used for LLaMA training
Amazonbot: Amazon's crawler for Alexa and AI services
AppleBot-Extended: Apple's AI training crawler (separate from search)
Cohere-ai: Cohere's enterprise AI crawler
AI2Bot: Allen Institute for AI crawler

Checking Crawler Access

To verify your robots.txt is configured correctly:

Visit yoursite.com/robots.txt directly
Use Google's robots.txt Tester in Search Console
Check server logs for AI crawler visits
Use online robots.txt validators

Beyond robots.txt

To maximize AI crawler effectiveness:

Create an llm.txt file with a summary of your site
Add JSON-LD schema markup for better content understanding
Keep your sitemap.xml updated with recent lastmod dates
Ensure fast page load times (slow sites may be partially crawled)
Use semantic HTML structure

Get AI-Optimized Visibility

Cite.sh is an AI Citation Directory with robots.txt optimized for all major AI crawlers. Get listed and earn a DR 26 dofollow backlink.

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Related Resources

For more on AI optimization, check out: