AI Crawlers and How to Block Them with robots.txt
As AI continues to reshape the web, a growing number of bots are crawling sites to collect content for training large language models. This article explains what AI crawlers are, why they matter, and how to block them using robots.txt.
Key Takeaways
- AI crawlers collect web content to train or improve AI models.
- You can allow or block these bots using the
robots.txtstandard. - Ethical AI companies honor these rules—but some crawlers ignore them.
AI crawlers are specialized bots that scan websites not for search indexing, but for extracting information to power artificial intelligence systems. This includes text, images, structured data, and APIs. Their presence raises questions about data ownership, consent, and protection of proprietary or sensitive content.
What Are AI Crawlers?
AI crawlers are automated programs that visit web pages to collect content for machine learning and generative AI. Unlike traditional search engine bots (like Googlebot), AI bots often use this data behind the scenes to feed or improve large language models.
Examples of AI Crawlers
Here are some well-known AI crawlers:
GPTBot(OpenAI)Google-Extended(Google AI models)CCBot(Common Crawl)anthropic-aiandClaude-Web(Claude by Anthropic)Bytespider,img2dataset,Omgili,FacebookBot(used for scraping or training)
These bots do not index pages for search. They ingest your site’s content into AI training pipelines—sometimes with permission, sometimes not.
AI Crawler Applications
AI crawlers are used for a range of purposes:
- LLM training: Ingesting articles, docs, and forums to improve models like GPT or Claude.
- Chatbot response tuning: Gathering structured Q&A or conversational content.
- Pricing and product research: Crawling e-commerce and SaaS pricing pages.
- Dataset enrichment: Collecting user-generated content, documentation, code snippets.
While these use cases benefit AI systems, they often do not benefit content creators, especially if data is used without clear consent.
How to Block AI Crawlers
To opt out of AI model training, use the standard robots.txt protocol. You publish a text file at the root of your domain, and bots will read it to determine what they are allowed to crawl.
Example: Blocking Known AI Bots
# Block AI bots
User-agent: GPTBot
Disallow: /
User-agent: Google-Extended
Disallow: /
User-agent: CCBot
Disallow: /
User-agent: img2dataset
Disallow: /
User-agent: anthropic-ai
Disallow: /
User-agent: Claude-Web
Disallow: /
User-agent: Omgilibot
Disallow: /
User-agent: Omgili
Disallow: /
User-agent: FacebookBot
Disallow: /
User-agent: Bytespider
Disallow: /
User-agent: magpie-crawler
Disallow: /
# Allow everything else
User-agent: *
Allow: /This configuration explicitly tells the most common AI crawlers not to access your site.
How to Implement It
- Create a file named
robots.txt - Paste the content above (or your variation)
- Place it at the root of your domain:
https://yourdomain.com/robots.txt - Ensure it’s served with
text/plaincontent type - Test it using
curl https://yourdomain.com/robots.txtto confirm visibility
If you’re hosting on a static service like S3 + CloudFront, put the file directly into your build output or in the public directory.
What About Non-Compliant Bots?
Not all bots follow the rules.
- Ethical AI companies like OpenAI, Google, and Anthropic respect
robots.txt. - Other crawlers may ignore it and scrape content anyway.
If you’re concerned about this, consider combining robots.txt with server-level blocking (e.g., IP filtering, rate limiting) or JavaScript-based obfuscation—but these come with tradeoffs.
Conclusion
AI crawlers are not going away. They’re already shaping the tools we use daily. As a site owner or product team, you should decide whether you want your content included in that process. Thankfully, robots.txt gives you a simple way to express that preference—and most reputable AI companies will respect it.
FAQs
Search engine crawlers index pages for public search results. AI crawlers collect data to train or improve machine learning models, often for use cases like chatbots or content generation.
Most reputable AI companies like OpenAI, Google, and Anthropic do respect it. Others may not. There is no enforcement mechanism—it's voluntary.
Yes. You can disallow AI-specific bots like GPTBot or Google-Extended, and still allow Googlebot by not blocking it.
They should stop crawling your site, and your content won’t be used in future training runs. But already-collected data may remain.
At the root of your site: <https://yourdomain.com/robots.txt>. It must be publicly accessible.