AI Crawler Bots Explained: GPTBot, ClaudeBot, and More

A new generation of web crawlers is scanning the internet, and they are not working for search engines. AI crawler bots, operated by companies like OpenAI, Anthropic, Perplexity, and Google, are systematically indexing web content to train AI models and power real-time AI responses.

Understanding these crawlers -- what they are, how they work, and how to manage access -- is essential for any brand that cares about its visibility in AI-generated answers. This guide covers everything you need to know about AI crawler bots in 2026.

What Are AI Crawler Bots?

AI crawler bots are automated programs that visit websites, read their content, and send that content back to AI companies. This content serves two primary purposes:

1. Training data: The content is used to train or fine-tune AI models, teaching them about brands, products, concepts, and facts.
2. Real-time retrieval: Some crawlers collect content to answer user questions in real time, pulling in fresh information during conversations.

These crawlers follow the same basic mechanics as traditional search engine crawlers -- they request pages via HTTP, parse the HTML, and follow links -- but their purpose and behavior differ in important ways.

The Major AI Crawler Bots

Here is a comprehensive breakdown of the AI crawlers you should know about.

GPTBot (OpenAI)

| Property | Details | |----------|---------| | Operator | OpenAI | | User-Agent | GPTBot | | Purpose | Training data collection | | First Seen | August 2023 | | Respects robots.txt | Yes |

GPTBot is OpenAI's primary crawler for collecting training data. It visits web pages to gather content that may be used in future model training. GPTBot does not perform real-time retrieval during ChatGPT conversations -- that is handled by a separate crawler.

OpenAI has stated that GPTBot filters out content behind paywalls, content that violates their usage policies, and personally identifiable information. Pages crawled by GPTBot may influence how future GPT models understand and describe your brand.

ChatGPT-User (OpenAI)

| Property | Details | |----------|---------| | Operator | OpenAI | | User-Agent | ChatGPT-User | | Purpose | Real-time browsing during conversations | | Respects robots.txt | Yes |

ChatGPT-User is the crawler that activates when a ChatGPT user asks the model to browse the web or when the model decides it needs fresh information. Unlike GPTBot, this crawler operates in real time -- when a user asks "What are the latest features of [your product]?", ChatGPT-User may visit your website to find the answer.

This distinction matters: blocking GPTBot stops training data collection, while blocking ChatGPT-User prevents your site from being referenced in real-time conversations.

ClaudeBot (Anthropic)

| Property | Details | |----------|---------| | Operator | Anthropic | | User-Agent | ClaudeBot | | Purpose | Training data collection | | Respects robots.txt | Yes |

ClaudeBot crawls websites to collect content for training Anthropic's Claude models. Anthropic has published documentation about ClaudeBot's behavior and provides clear instructions for blocking it via robots.txt.

anthropic-ai (Anthropic)

| Property | Details | |----------|---------| | Operator | Anthropic | | User-Agent | anthropic-ai | | Purpose | Training data collection (legacy) | | Respects robots.txt | Yes |

This is Anthropic's earlier crawler user-agent. Some deployments still use this identifier. If you want to manage Anthropic's access comprehensively, block or allow both ClaudeBot and anthropic-ai in your robots.txt.

PerplexityBot (Perplexity)

| Property | Details | |----------|---------| | Operator | Perplexity | | User-Agent | PerplexityBot | | Purpose | Real-time search and retrieval | | Respects robots.txt | Partially (has been controversial) |

PerplexityBot powers Perplexity's search-first AI experience. Unlike most AI crawlers that collect training data, PerplexityBot primarily performs real-time retrieval -- it searches the web when users ask questions and pulls in current information to generate cited answers.

Perplexity's approach is closest to a traditional search engine, as it provides source citations alongside its responses. However, there have been concerns about PerplexityBot not consistently respecting robots.txt directives, which led to some controversy in 2024 and 2025.

Google-Extended (Google)

| Property | Details | |----------|---------| | Operator | Google | | User-Agent | Google-Extended | | Purpose | AI training (Gemini models) | | Respects robots.txt | Yes |

Google-Extended is the crawler Google uses specifically for AI model training, separate from Googlebot which handles search indexing. This separation is important: you can block Google-Extended to prevent your content from training Gemini models while still allowing Googlebot to index your site for Google Search.

Bingbot (Microsoft)

| Property | Details | |----------|---------| | Operator | Microsoft | | User-Agent | bingbot | | Purpose | Search indexing and Copilot/Bing Chat | | Respects robots.txt | Yes |

Bingbot serves double duty. It crawls content for Bing's search index, but that same content also powers Microsoft Copilot and Bing Chat. There is no separate crawler for Microsoft's AI features -- blocking Bingbot blocks both search indexing and AI access.

This makes Bingbot a unique case: unlike Google's separated approach (Googlebot vs. Google-Extended), Microsoft bundles everything into one crawler.

How AI Crawlers Differ from Traditional Search Crawlers

While AI crawlers share technical similarities with search engine crawlers, there are fundamental differences in how they use the content they collect.

Purpose of Crawling

Search engine crawlers index content to display in search results. Your page appears as a link with a snippet, and users click through to your site.

AI crawlers collect content to either train models or answer questions directly. Your content may be synthesized, paraphrased, or summarized in an AI response without users ever visiting your site.

Content Usage

Search engines generally show snippets of your content and link back to the source.

AI platforms may incorporate your content into responses without direct attribution. Some platforms (like Perplexity) cite sources, while others (like ChatGPT) do not consistently attribute information.

Crawl Frequency

Search engine crawlers revisit pages regularly to detect updates, with popular pages crawled more frequently.

AI training crawlers (GPTBot, ClaudeBot) may crawl less frequently since they collect data for periodic model training rather than continuous indexing. Real-time crawlers (ChatGPT-User, PerplexityBot) crawl on demand when users ask relevant questions.

Impact of Blocking

Blocking Googlebot removes your site from Google search results -- a significant traffic consequence.

Blocking AI crawlers prevents your content from influencing AI responses. This means AI platforms may still mention your brand based on older training data or third-party sources, but potentially with less accuracy.

How to Configure robots.txt for AI Crawlers

The primary mechanism for controlling AI crawler access is your robots.txt file, located at the root of your domain.

Allowing All AI Crawlers (Recommended for AEO)

If your goal is to maximize AI visibility, allow all crawlers:

# Allow all AI crawlers
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: /

Blocking Specific AI Crawlers

If you want to block specific crawlers while allowing others:

# Block training data collection, allow real-time browsing
User-agent: GPTBot
Disallow: /

User-agent: ChatGPT-User
Allow: /

User-agent: ClaudeBot
Disallow: /

User-agent: Google-Extended
Disallow: /

Partial Access

You can allow crawlers to access some sections while blocking others:

# Allow AI crawlers to access public content only
User-agent: GPTBot
Allow: /blog/
Allow: /docs/
Allow: /about/
Disallow: /account/
Disallow: /api/
Disallow: /admin/

Important Limitations

• robots.txt is advisory: Crawlers are expected to respect it, but compliance is not technically enforced.
• Cached training data persists: Blocking a crawler today does not remove content already collected and used in model training.
• Not all crawlers are known: Smaller AI companies may use crawlers that are not well-documented.

Why Allowing AI Crawlers Matters for Brand Visibility

Many brands reflexively block AI crawlers, treating them as content scrapers. This is a strategic mistake for most organizations. Here is why:

AI Responses Are the New First Impression

When a potential customer asks an AI assistant about your product category, the AI's response is their first impression of your brand. If the AI cannot access your current content, it relies on older training data or third-party descriptions -- which may be outdated, incomplete, or unfavorable.

Real-Time Retrieval Is Growing

More AI platforms are incorporating real-time web retrieval. ChatGPT, Perplexity, and Gemini can all browse the web during conversations. If you block their crawlers, these platforms cannot reference your latest content, pricing, or features.

Training Data Shapes Long-Term Perception

The content AI models train on shapes their understanding of your brand for months or years. Allowing training data crawlers ensures that AI models have access to your authoritative, first-party content rather than relying solely on third-party descriptions.

Blocking Does Not Prevent Mentions

Blocking AI crawlers does not prevent AI platforms from mentioning your brand. They will still discuss you based on existing training data and third-party sources. Blocking simply means you lose the ability to influence what they say with your own content.

Beyond robots.txt: Enhancing AI Crawler Access

Allowing crawler access is the minimum. To maximize the value AI platforms extract from your site:

Implement an llms.txt File

The llms.txt standard provides a machine-readable summary of your site specifically designed for AI consumption. It tells AI platforms what your brand is, what you offer, and where to find key information. You can generate an llms.txt file for free using Orbilo's tool.

Add Structured Data Markup

JSON-LD schema markup helps AI crawlers understand the structure and meaning of your content. Use it to mark up:

• Organization information
• Product details and pricing
• FAQ content
• How-to guides
• Reviews and ratings

Optimize Content Structure

AI crawlers extract more value from well-structured content:

• Use clear heading hierarchies (H1, H2, H3)
• Write descriptive meta descriptions
• Include summary paragraphs at the top of pages
• Use lists and tables for structured information
• Avoid content locked behind JavaScript rendering when possible

Check Your AEO Score

Use Orbilo's free AEO Score tool to evaluate how well your content is optimized for AI platforms. It analyzes your pages for factors that affect AI crawler comprehension and provides actionable recommendations.

Monitoring AI Crawler Activity

Server Log Analysis

Check your server logs to see which AI crawlers are visiting your site, how often, and which pages they access. Look for user-agent strings containing GPTBot, ClaudeBot, PerplexityBot, ChatGPT-User, and Google-Extended.

Testing AI Responses

The most direct way to measure the impact of AI crawler access is to test how AI platforms respond to queries about your brand. Run regular queries across ChatGPT, Claude, Perplexity, and Grok to see if your content is being reflected accurately.

Orbilo's brand monitoring platform automates this process, running your prompts across all major AI platforms and tracking changes in mention frequency, sentiment, and accuracy over time.

Next Steps

• What is llms.txt? - Learn about the new standard for AI-readable content
• What is AEO? - Foundational guide to Answer Engine Optimization
• How to Audit Your Brand's AI Presence - Step-by-step guide to testing your AI visibility

Want to track how AI platforms represent your brand? Start monitoring with Orbilo and get alerts when your AI mentions change.