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Crawlers

Understanding AI Crawlers: The Complete Guide for 2025

Discover everything you need to know about AI crawlers, from GPTBot to ClaudeBot. Learn how to control access, optimize for AI visibility, and prepare for the AI-powered web.

Nicolas Ilhe••6 min read

The web is experiencing a fundamental shift. While traditional search engines like Google have dominated how content is discovered for decades, a new generation of AI crawlers is quietly reshaping the digital landscape. These automated bots don't just index content for search results—they feed the large language models (LLMs) that power ChatGPT, Claude, Gemini, and other AI systems that millions of people use daily.

If you're a website owner, content creator, or digital marketer, understanding AI crawlers isn't just important—it's essential for staying relevant in the AI-powered web of tomorrow.

What Are AI Crawlers?

AI crawlers are specialized web robots that do more than index pages for search engines—they harvest public content in bulk to train large-language models (LLMs) or fetch pages on-demand to power AI assistants. Unlike traditional crawlers, they can generate significant traffic loads or bypass typical crawling rules when triggered by user queries.

Types of AI Crawlers

Training Bots

Continuously scan the public web to build datasets for model pre-training (e.g., GPTBot, ClaudeBot).

Indexing Bots

Construct specialized search indexes for AI-powered search features (e.g., OAI-SearchBot, PerplexityBot).

On-Demand Fetchers

Activate only when a user requests live page content via an AI assistant (e.g., ChatGPT-User, Claude-User, Perplexity-User).

AI Crawlers by Provider

OpenAI

GPTBot

  • Purpose: Bulk collection of public web pages to train GPT models.
  • User-Agent: Mozilla/5.0 … (compatible; GPTBot/1.0; +https://openai.com/gptbot)
  • Frequency: Continuous, undisclosed schedule.

OAI-SearchBot

  • Purpose: Index builder for ChatGPT's integrated Search feature.
  • User-Agent: …compatible; OAI-SearchBot/1.0; +https://openai.com/searchbot)
  • Frequency: Periodic, undisclosed.

ChatGPT-User

  • Purpose: On-demand fetcher when a user invokes ChatGPT's web browsing.
  • User-Agent: …compatible; ChatGPT-User/1.0; +https://openai.com/bot)
  • Trigger: Only on user request.

Source: OpenAI Bots documentation

Anthropic

ClaudeBot

  • Purpose: Continuous crawl for training Anthropic's Claude models.
  • User-Agent: …compatible; ClaudeBot/1.0; +https://www.anthropic.com/)
  • Frequency: Continuous, undisclosed.

Claude-SearchBot

  • Purpose: Index refinement for Claude's internal search.
  • User-Agent: Claude-SearchBot
  • Frequency: Undisclosed.

Claude-User

  • Purpose: On-demand page fetcher for live Claude queries.
  • User-Agent: Claude-User
  • Trigger: Only on user request.

Source: Anthropic Support – crawler details

Perplexity AI

PerplexityBot

  • Purpose: Builds Perplexity's AI search index (not used for LLM pre-training).
  • User-Agent: Mozilla/5.0 … (compatible; PerplexityBot/1.0; +https://perplexity.ai/perplexitybot)
  • Frequency: Undisclosed; respects robots.txt.

Perplexity-User

  • Purpose: On-demand fetcher when a user clicks a Perplexity citation.
  • User-Agent: …compatible; Perplexity-User/1.0; +https://perplexity.ai/perplexity-user)
  • Trigger: Only on user action; generally ignores robots.txt.

Source: Perplexity Crawlers guide

Google

Googlebot / Google-Extended

  • Purpose:
    • Googlebot: Standard web indexing for Search.
    • Google-Extended: Additional crawl for Gemini/Bard/Vertex AI.
  • User-Agent: Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html) plus an optional Google-Extended token.
  • Frequency: Dynamic "crawl-budget" algorithm; adjustable via Search Console (valid 90 days).

Source: Google Crawler Overview

Microsoft

Bingbot

  • Purpose: Crawls for Bing Search and supplies data to Bing Chat/Copilot.
  • User-Agent: …compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)
  • Frequency: Variable; hourly control via Bing Webmaster Tools' "Crawl Control."

Source: Bing Crawl Control docs

Apple

Applebot / Applebot-Extended

  • Purpose: Indexes for Siri, Spotlight, and Apple Intelligence; Extended variant signals opt-in for AI training.
  • User-Agent:
    • Applebot/0.1 (+http://www.apple.com/go/applebot)
    • Applebot-Extended/1.0 (+http://www.apple.com/go/applebot)
  • Frequency: Irregular; triggered by user queries or internal schedules.

Source: Apple Support – About Applebot

Amazon

Amazonbot

  • Purpose: Feeds Alexa and other Amazon AI services with web content.
  • User-Agent: Mozilla/5.0 … Safari/600.2.5 … (Amazonbot/0.1; +https://developer.amazon.com/support/amazonbot)
  • Frequency: Undisclosed; respects robots.txt but ignores Crawl-delay.

Source: Amazon Developers – About Amazonbot

Meta (Facebook)

facebookexternalhit

  • Purpose: Generates OpenGraph previews when links are shared.
  • User-Agent: facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)
  • Trigger: On-demand when content is shared on Meta platforms.

Meta-ExternalAgent / Meta-ExternalFetcher

  • Purpose:
    • ExternalAgent: Continuous crawl for AI training data.
    • ExternalFetcher: On-demand fallback when previews require deeper fetch.
  • User-Agents:
    • meta-externalagent/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/crawler)
    • meta-externalfetcher/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/crawler)
  • Frequency: ExternalAgent undisclosed; ExternalFetcher on-demand.

Source: Meta Web Crawlers docs

Common Crawl

CCBot

  • Purpose: Builds an open-data web archive used by researchers and many AI projects.
  • User-Agent: CCBot/2.0 (+https://commoncrawl.org/)
  • Frequency: Approximately monthly full-web crawls.

Source: Common Crawl

Other Notable AI Crawlers

  • Bytespider (ByteDance): LLM-training crawler (frequency undisclosed). Source
  • YouBot (You.com): AI search indexer (frequency undisclosed). Source
  • Diffbot, Cohere-AI, Panscient, SemrushBot, etc.: Various purposes; most schedules not publicly disclosed.

Best Practices for Tracking & Management

Log Analysis & UA Detection

Regularly scan your server logs for the User-Agent tokens listed above to quantify AI-crawler traffic. For deeper insights—such as request rates over time, burst patterns, and unexpected crawlers—use Qwairy Crawler Analytics, which automatically parses logs, tags known AI bots, and highlights anomalies.

robots.txt Configuration & Validation

Define explicit User-agent: rules in your robots.txt to allow or block each crawler. Then, verify compliance directly in the Qwairy dashboard: it checks your live robots.txt, flags syntax errors, and simulates how each AI crawler will interpret your directives, ensuring you don't accidentally over- or under-expose content.

Crawler Analytics & Monitoring

Beyond classical webmaster tools, rely on Qwairy Crawler Analytics to:

  • Visualize AI-bot traffic alongside traditional crawlers in real time.
  • Set alerts when any bot exceeds your defined thresholds (e.g. GPTBot requests > 100/min).
  • Export periodic reports to track trends and demonstrate the ROI of your crawl-management strategy.

FAQ

What are AI crawlers and how do they differ from traditional crawlers?

AI crawlers are specialized web robots that harvest public content to train large language models (LLMs) or fetch pages on-demand for AI assistants. Unlike traditional crawlers that primarily index for search results, AI crawlers can generate significant traffic loads and may bypass typical crawling rules when triggered by user queries.

What are the main types of AI crawlers?

There are three main types:

  • Training Bots: Continuously scan the web for model pre-training (e.g., GPTBot, ClaudeBot)
  • Indexing Bots: Build specialized search indexes (e.g., OAI-SearchBot, PerplexityBot)
  • On-Demand Fetchers: Activate only when users request live content (e.g., ChatGPT-User, Claude-User)

Which companies operate the most important AI crawlers?

The major AI crawler operators include:

  • OpenAI: GPTBot, ChatGPT-User, OAI-SearchBot
  • Anthropic: ClaudeBot, Claude-User, Claude-SearchBot
  • Google: Google-Extended
  • Microsoft: Bingbot
  • Apple: Applebot, Applebot-Extended
  • Amazon: Amazonbot
  • Meta: Meta-ExternalAgent, facebookexternalhit
  • Perplexity AI: PerplexityBot, Perplexity-User
  • Common Crawl: CCBot

How can I track and monitor AI crawler activity on my website?

You can track AI crawlers by:

  • Regularly scanning server logs for specific User-Agent tokens
  • Using specialized tools like Qwairy Crawler Analytics for real-time monitoring and anomaly detection
  • Setting up alerts when bots exceed defined thresholds
  • Exporting periodic reports to track trends and ROI

How do I control which AI crawlers can access my website?

Control AI crawler access through your robots.txt file by defining explicit User-agent rules for each crawler. You can:

  • Allow all AI crawlers
  • Block specific training crawlers while allowing search bots
  • Block all AI crawlers completely

Tools like Qwairy can help validate your robots.txt configuration and simulate how each crawler will interpret your directives.

Want to track AI crawler activity on your website and optimize your AI visibility? Try Qwairy's AI Traffic Analysis to monitor how AI systems interact with your content and make data-driven decisions about your AI crawler strategy.

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