Before AI models can recommend your business, they need to learn about it. Most AI platforms learn from the public web — and to do that, they use web crawlers (also called bots or spiders) that visit websites, read their content, and add it to training datasets or live retrieval indexes.
Understanding which crawlers exist, what they do, and how to control them is essential for technical AI visibility optimization.
The AI Crawler Ecosystem
As of 2026, the major AI crawlers you need to know about:
| Crawler | Company | User Agent String | Purpose |
|---|---|---|---|
| GPTBot | OpenAI | GPTBot | ChatGPT training data |
| Google-Extended | Google | Google-Extended | Gemini AI training (separate from search) |
| anthropic-ai | Anthropic | anthropic-ai | Claude training data |
| Claude-Web | Anthropic | Claude-Web | Claude web retrieval |
| PerplexityBot | Perplexity | PerplexityBot | Perplexity real-time retrieval |
| Meta-ExternalAgent | Meta | meta-externalagent | Meta AI training |
| Bytespider | ByteDance | Bytespider | TikTok/Doubao AI training |
| CCBot | Common Crawl | CCBot | Open dataset (many AI companies use this) |
| Cohere-AI | Cohere | cohere-ai | Cohere AI training |
Two Types of AI Crawlers
Understanding the difference between training crawlers and retrieval crawlers changes your optimization strategy:
Training Data Crawlers
These crawlers collect content to be used in model training — the process that determines what an AI model "knows" about the world:
- GPTBot (OpenAI)
- Google-Extended (Google AI training)
- anthropic-ai (Anthropic)
- Meta-ExternalAgent (Meta AI)
- CCBot (Common Crawl)
Key characteristic: Training happens offline, before the model is deployed. Content collected by these crawlers influences what the model learned during training, which may be months or years in the past by the time users interact with the model.
Optimization implication: Allowing these crawlers ensures your current web content will be incorporated in future model training cycles. Blocking them means your business will be less well-represented in trained models.
Real-Time Retrieval Crawlers
These crawlers retrieve current web content at query time to supplement model responses:
- PerplexityBot (Perplexity)
- Claude-Web (Anthropic Claude with web access)
- Googlebot (also used for Google's retrieval-based AI Mode)
Key characteristic: Retrieval happens at the moment of a user query. Content changes on your website are reflected in AI responses much more quickly.
Optimization implication: These crawlers benefit from current, well-structured content. Blocking them means AI platforms can't retrieve real-time information about your business, reducing your retrieval-based visibility.
How to View AI Crawlers in Your Logs
Check your web server access logs for AI crawler activity:
Apache/Nginx logs:
grep -i "gptbot\|google-extended\|anthropic\|perplexitybot" /var/log/nginx/access.log
Cloudflare Analytics: In Cloudflare dashboard → Analytics → Bots, you can see bot traffic by type.
Google Search Console: Doesn't show AI crawlers specifically, but shows total crawl activity. Use the URL Inspection tool to see what Googlebot sees.
Controlling AI Crawler Access with robots.txt
Your robots.txt file controls crawler access to your site. For each AI crawler, you can choose to allow or disallow access to some or all of your site.
Full Access (Recommended for most businesses)
Allow all AI crawlers to access everything:
User-agent: *
Allow: /
# Disallow private/app areas
User-agent: *
Disallow: /admin/
Disallow: /dashboard/
Disallow: /api/private/
No special AI entries needed — User-agent: * allows all crawlers.
Selective Blocking
Allow AI training crawlers but block retrieval crawlers (useful if you want to protect current content from AI scraping while allowing training):
User-agent: PerplexityBot
Disallow: /
User-agent: Claude-Web
Disallow: /
User-agent: GPTBot
Allow: /
Complete AI Training Block
Allow search indexing but block all AI training:
User-agent: GPTBot
Disallow: /
User-agent: Google-Extended
Disallow: /
User-agent: anthropic-ai
Disallow: /
User-agent: CCBot
Disallow: /
User-agent: Meta-ExternalAgent
Disallow: /
The Standard AI Visibility Optimization Config
For businesses optimizing for AI visibility:
# Allow Googlebot fully
User-agent: Googlebot
Allow: /
# Allow AI training crawlers
User-agent: GPTBot
Allow: /
User-agent: Google-Extended
Allow: /
User-agent: anthropic-ai
Allow: /
User-agent: PerplexityBot
Allow: /
User-agent: Claude-Web
Allow: /
# Block private areas from all
User-agent: *
Disallow: /admin/
Disallow: /dashboard/
Disallow: /private/
The Copyright and Consent Question
An important consideration: most AI training data collection happens without explicit consent from website owners, beyond the implied consent of having a public website.
Several publisher groups and individual companies have actively blocked AI crawlers in response to:
- Concerns about their content being used to train commercial AI without compensation
- Concerns about AI-generated content that competes with their original work
- Legal uncertainty around the training data copyright question
If content rights are a concern for your business, blocking specific training crawlers is a legitimate choice. However, understand that blocking training crawlers reduces your training-data-based AI visibility — a real trade-off.
Page-Level Control with Meta Tags
For more granular control than robots.txt, you can block AI on specific pages using meta tags:
<!-- Block this specific page from AI training (OpenAI) -->
<meta name="robots" content="noai, noimageai">
<!-- Standard noindex (also affects some AI systems) -->
<meta name="robots" content="noindex">
The noai meta tag is an emerging convention, not yet universally supported. Different platforms may handle it differently.
What AI Crawlers Collect
When AI crawlers visit your pages, they typically collect:
- Text content — All visible text on the page
- Title and meta description — Page-level metadata
- Structured data — JSON-LD schema markup
- Alt text — Image descriptions
- Link structure — Internal and external links
They generally do NOT collect:
- Personal user data or cookies
- Login-protected content
- Dynamic content loaded via JavaScript (varies by crawler sophistication)
- Content in iframes from other domains
Optimizing Your Content for AI Crawlers
Once you've decided which crawlers to allow, ensure your content is crawler-friendly:
1. Server-side rendering: Critical content should be in the HTML response, not rendered by JavaScript. Many AI crawlers have limited JavaScript execution.
2. Clean, semantic HTML: Use proper <h1>, <h2>, <p>, <ul> structure. Crawlers parse semantic HTML more reliably than div-soup.
3. Comprehensive schema markup: JSON-LD in the <head> provides structured data that all crawlers can read, regardless of JavaScript execution.
4. Fast loading: Crawlers have timeout limits. Pages that load slowly may be partially crawled or skipped.
5. Accessible text: Avoid encoding important information in images without alt text, or in PDFs without text versions.
Q: Does blocking GPTBot hurt my Google search rankings? A: No. GPTBot (OpenAI) and Googlebot are completely separate systems. Blocking GPTBot affects only OpenAI's access to your content, not your Google search rankings in any way.
Q: How do I verify which AI crawlers are visiting my site? A: Review your server access logs as described above. You can also use a hosting analytics tool that breaks down bot traffic. If you use Cloudflare, their Bot Management dashboard provides crawler categorization.
Q: Should I disallow CCBot? A: Common Crawl is used by many AI companies as training data. Blocking it reduces your presence across a wide range of AI training datasets. For most businesses optimizing for AI visibility, allowing CCBot is recommended.