AI Crawler Bots Explained: GPTBot, ClaudeBot, and More

A new generation of web crawlers is visiting your website, and they are not from traditional search engines. AI companies like OpenAI, Anthropic, Google, and Perplexity now operate their own crawler bots that scan websites to gather training data for their models and retrieve information for real-time AI responses. Understanding these crawlers, what they do, and how to control their access, is a foundational part of any Answer Engine Optimization strategy.

This guide covers the major AI crawler bots active today, explains what each one does, and walks through how to configure your robots.txt file to manage their access to your content.

What Are AI Crawler Bots?

AI crawler bots are automated programs that visit websites and collect content, much like Googlebot has done for traditional search for decades. However, AI crawlers serve a different purpose. Instead of indexing pages for a search results page, they collect content for two primary uses:

Training data collection: Content gathered by AI crawlers may be used to train or fine-tune large language models. This means your website's content could directly influence what the AI "knows" about your brand, your industry, and your competitors.

Real-time retrieval: Some AI crawlers fetch content in real time to help AI assistants provide up-to-date answers. When a user asks an AI about a topic, the system may send a crawler to relevant websites to retrieve current information before generating a response.

The distinction matters for your AEO strategy. Blocking a training crawler means the AI model may never learn about your brand from your own content. Blocking a retrieval crawler means the AI cannot cite your current information when answering user queries. Both have consequences for your brand's visibility in AI-generated responses.

The Major AI Crawler Bots

GPTBot (OpenAI)

User-Agent: GPTBot Operator: OpenAI Purpose: Training data collection

GPTBot is OpenAI's web crawler used to gather content for training future GPT models. When GPTBot visits your site, the content it collects may be used in the training process for models like GPT-4, GPT-5, and their successors.

OpenAI has stated that GPTBot filters out content behind paywalls, content that violates their policies, and content that contains personally identifiable information. However, the specifics of what gets included in training data are not fully transparent.

GPTBot identifies itself with a clear user-agent string and respects robots.txt directives. If you want your content included in OpenAI's training data, which can improve your brand's representation in ChatGPT responses, you should allow GPTBot access to your site.

ChatGPT-User (OpenAI)

User-Agent: ChatGPT-User Operator: OpenAI Purpose: Real-time content retrieval

ChatGPT-User is a separate crawler from GPTBot, and the distinction is important. While GPTBot collects data for model training, ChatGPT-User fetches content in real time when ChatGPT users browse the web or when the model needs current information to answer a question.

When a ChatGPT Plus or Enterprise user asks about recent events, product pricing, or other time-sensitive information, ChatGPT-User may visit your website to retrieve that information. Blocking this crawler means ChatGPT cannot access your current content when generating real-time responses, even if GPTBot previously crawled your site for training data.

For most brands pursuing AEO, allowing ChatGPT-User access is critical. It ensures that ChatGPT can reference your latest product information, pricing, and content when users ask relevant questions.

ClaudeBot (Anthropic)

User-Agent: ClaudeBot Operator: Anthropic Purpose: Training data collection

ClaudeBot is Anthropic's web crawler, used to gather content for training Claude models. Similar to GPTBot, ClaudeBot collects website content that may be incorporated into future versions of Claude.

Anthropic uses ClaudeBot to ensure Claude has broad knowledge of the web, including information about brands, products, and services. Allowing ClaudeBot access to your site means your content can directly inform how Claude describes your brand when users ask relevant questions.

ClaudeBot respects robots.txt directives and can be selectively allowed or blocked.

anthropic-ai (Anthropic)

User-Agent: anthropic-ai Operator: Anthropic Purpose: Real-time content retrieval and product features

Anthropic also operates a second crawler with the user-agent anthropic-ai. This crawler is used for product features that involve fetching web content in real time, similar to how ChatGPT-User operates for OpenAI.

When Claude users share URLs or when Claude needs to access current web content to answer questions, the anthropic-ai crawler may visit your site. Blocking this crawler means Claude cannot retrieve your current content during conversations, potentially leading to outdated or missing information about your brand.

PerplexityBot (Perplexity AI)

User-Agent: PerplexityBot Operator: Perplexity AI Purpose: Real-time content retrieval and indexing

PerplexityBot is particularly important for AEO because Perplexity's entire model is built around real-time web retrieval. Unlike ChatGPT or Claude, which rely primarily on training data with optional web browsing, Perplexity fetches and cites web sources for nearly every response.

When PerplexityBot crawls your site, it indexes your content for retrieval when users ask relevant questions. Perplexity also provides source citations in its responses, meaning your brand can get direct attribution and clickable links back to your content.

Blocking PerplexityBot has an outsized impact on your Perplexity visibility compared to blocking other AI crawlers, because Perplexity depends on real-time retrieval rather than pre-trained knowledge.

Google-Extended (Google)

User-Agent: Google-Extended Operator: Google Purpose: Training data for Gemini and other Google AI products

Google-Extended is Google's crawler specifically for AI training purposes, separate from Googlebot which handles traditional search indexing. Allowing or blocking Google-Extended does not affect your Google Search rankings. It only controls whether your content is used to train Google's AI products like Gemini.

This separation is important: you can block Google-Extended to prevent your content from training Gemini while still appearing in Google Search results via Googlebot. However, blocking Google-Extended may reduce your brand's presence in Gemini-generated responses, which is an increasingly important channel as Google integrates Gemini into its search experience.

Other Notable AI Crawlers

Several other AI crawlers are worth being aware of:

• Bytespider (ByteDance): Used for training AI models, including those powering TikTok's AI features
• CCBot (Common Crawl): An open dataset used by many AI companies for training data
• FacebookBot (Meta): While primarily used for link previews, Meta also uses crawled data for AI training
• cohere-ai (Cohere): Used by Cohere for training their enterprise AI models

Configuring robots.txt for AI Crawlers

Your robots.txt file is the primary mechanism for controlling which AI crawlers can access your content. This file sits at the root of your domain (e.g., https://example.com/robots.txt) and provides instructions to web crawlers about which pages they are allowed or not allowed to visit.

Allowing All AI Crawlers

If your AEO strategy prioritizes maximum visibility across all AI platforms, you should ensure your robots.txt does not block any AI crawlers. A permissive configuration looks like this:

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: /

You do not strictly need to add explicit Allow directives if your robots.txt does not block these bots. However, being explicit makes your intentions clear and ensures no wildcard rules accidentally block AI crawlers.

Selective Access

You may want to allow AI crawlers to access most of your site while blocking them from certain sections:

User-agent: GPTBot
Allow: /
Disallow: /internal/
Disallow: /staging/
Disallow: /admin/

User-agent: ClaudeBot
Allow: /
Disallow: /internal/
Disallow: /staging/
Disallow: /admin/

This approach lets AI models learn about your public-facing content while keeping internal pages, staging environments, and administrative areas private.

Blocking Specific Crawlers

If you want to allow most AI crawlers but block specific ones, you can use targeted rules:

User-agent: GPTBot
Disallow: /

User-agent: Bytespider
Disallow: /

User-agent: ClaudeBot
Allow: /

User-agent: PerplexityBot
Allow: /

Allowing Training but Blocking Retrieval (or Vice Versa)

You can make nuanced decisions about training versus real-time retrieval:

# Allow training data collection
User-agent: GPTBot
Allow: /

# Block real-time retrieval
User-agent: ChatGPT-User
Disallow: /

This configuration means OpenAI can use your content for training (so future models know about your brand) but ChatGPT cannot fetch your current content during conversations. This approach might make sense if you want AI models to have general knowledge of your brand but do not want your real-time content scraped for immediate use.

Why AI Crawler Configuration Matters for AEO

Your robots.txt configuration directly affects your Answer Engine Optimization in several ways.

Training Data Inclusion

If AI crawlers cannot access your site, the AI models they train will have limited knowledge of your brand. They will only know about you through third-party sources like news articles, reviews, and forum discussions. While third-party content is valuable, you lose the ability to shape the narrative when the AI cannot read your own content.

Real-Time Accuracy

Blocking retrieval crawlers like ChatGPT-User and PerplexityBot means AI platforms cannot check your current information. If your pricing changes, your product adds new features, or you rebrand, the AI will continue referencing outdated information until the next model training cycle.

Citation and Attribution

Perplexity and other retrieval-based AI platforms cite their sources. If PerplexityBot can access your content, users may see direct links to your website in AI-generated responses. This creates a direct traffic channel from AI platforms to your site, something that is lost if you block the crawler.

Competitive Advantage

If your competitors block AI crawlers but you allow them, AI platforms will have more and better information about your brand than your competitors. This can lead to your brand being mentioned more frequently and more favorably in AI-generated responses.

Beyond robots.txt: Complementary Approaches

While robots.txt is the foundation of AI crawler management, several complementary approaches can enhance your strategy.

llms.txt Files

The llms.txt standard provides a structured file specifically designed for AI consumption. Unlike robots.txt, which controls access, llms.txt proactively provides AI models with the information you want them to know about your brand. Orbilo offers a free llms.txt generator to help you create this file.

JSON-LD Schema Markup

Structured data through JSON-LD helps AI crawlers understand the semantic meaning of your content. When a crawler visits a product page with proper JSON-LD markup, it can extract structured information about pricing, features, reviews, and availability rather than trying to parse unstructured HTML.

Sitemap Optimization

An XML sitemap helps AI crawlers discover all the important pages on your site. Ensure your sitemap is up to date, includes all pages you want AI models to know about, and is referenced in your robots.txt file.

Content Structure

How you structure your content affects how well AI crawlers can extract useful information. Clear headings, concise paragraphs, bulleted lists for features, and FAQ sections all help AI crawlers understand and extract your content more effectively.

Monitoring AI Crawler Activity

Understanding which AI crawlers visit your site and what they access helps you refine your strategy.

Server Log Analysis

Your web server logs record every crawler visit, including the user-agent string. Analyze these logs to see which AI crawlers visit most frequently, which pages they access, and how their behavior changes over time.

Analytics Tools

Some analytics platforms now identify AI crawler traffic specifically. Look for traffic segments with AI-related user-agent strings to understand the volume and patterns of AI crawler visits.

AI Platform Monitoring

Beyond tracking crawler visits, monitor how AI platforms actually mention your brand. Use tools like Orbilo to run systematic tests across ChatGPT, Claude, Perplexity, and other platforms. This shows you whether allowing or adjusting crawler access correlates with improvements in how your brand is represented.

You can check your AEO Score for free to get a baseline understanding of how well your content is currently optimized for AI consumption.

Recommendations for Most Brands

For the majority of brands pursuing AEO, the recommended approach is:

1. Allow all major AI crawlers access to your public-facing content
2. Block crawlers from internal, staging, admin, and sensitive content
3. Create an llms.txt file to proactively provide AI-friendly brand information
4. Implement JSON-LD schema markup on key pages
5. Monitor AI platform mentions to track the impact of your crawler configuration
6. Review and update your robots.txt quarterly as new AI crawlers emerge

The AI crawler landscape evolves quickly. New bots appear regularly, and existing ones change their behavior. Staying informed and periodically auditing your configuration ensures you maintain optimal visibility across all AI platforms.

Next Steps

• What is llms.txt? - Learn about the new standard for AI-readable content
• How to Optimize Your Content for AI Search Engines - Structure your content for maximum AI visibility
• What is Answer Engine Optimization? - Understand the broader AEO landscape

Want to monitor how AI platforms mention your brand? Start tracking with Orbilo across ChatGPT, Claude, Perplexity, Grok, and more.