In this blog, we’ll explore what llm.txt is, how it works, why it’s important for website owners and AI developers alike, and how to use it to control how your content is accessed and used by AI crawlers.
What Is llm.txt?
llm.txt is a simple text file placed in the root directory of a website (like https://example.com/llm.txt) that tells AI crawlers whether they can use the site’s content for training or inference purposes. Inspired by the long-established robots.txt protocol for search engines, llm.txt is designed to give content creators and website owners a voice in how their data is used by LLMs.
As AI companies move toward greater transparency and ethical data usage, respecting llm.txt is becoming a best practice for LLM crawlers.
Why Do We Need llm.txt?
AI models are hungry for data. To improve language understanding and generation, they need to be trained on a wide range of human-generated text—from blogs and forums to documentation and product descriptions.
However, not all website owners are comfortable with their content being used to train AI models, especially when:
- It involves copyrighted or sensitive information
- It might impact SEO rankings
- It’s used without proper attribution or consent
The llm.txt file is a step toward consensual web crawling for AI, letting publishers explicitly opt in or out of this process.
How Does llm.txt Work?
Much like robots.txt, the llm.txt file provides simple instructions for AI crawlers. These instructions can:
- Allow or disallow access to all or parts of the website
- Specify particular crawlers (like OpenAI, Anthropic, Google DeepMind, etc.)
- Set conditions for usage (e.g., inference only, no training)
Here’s a basic example of what an llm.txt file might look like:
# Disallow OpenAI from training on site content
User-Agent: OpenAI
Disallow: /
# Allow Anthropic but only for inference
User-Agent: Anthropic
Allow: /
Usage: inference-only
# Allow Google DeepMind for both training and inference
User-Agent: DeepMind
Allow: /
These are fictional instructions, but they demonstrate how flexible and readable the llm.txt format can be.
Benefits of Using llm.txt
- Control Over Content Use
Website owners can explicitly state how their content should or should not be used by AI companies.
- Transparency & Ethics
For AI developers, checking for and respecting llm.txt aligns with ethical data practices and fosters trust with the public.
- Granular Permissions
You can choose to allow some models but block others—or allow inference while disallowing training.
- Easy Implementation
The file is plain text, easy to write, and doesn’t require any software changes to your site.
How LLM Crawlers Use llm.txt
Not all AI crawlers currently support or check llm.txt, but adoption is growing. Major LLM providers are under increasing pressure to demonstrate transparency and respect for data ownership. By voluntarily honoring llm.txt, these companies can avoid legal risk and build public trust.
In practice, a crawler will:
- Request https://example.com/llm.txt
- Parse the file for user-agent instructions
- Obey the allow/disallow rules before crawling or using any data
Best Practices for Using llm.txt
- Be Specific: Name the AI crawler (user-agent) you want to target. Use commonly recognized names like OpenAI, Anthropic, Mistral, etc.
- Host It at the Root: Just like robots.txt, it should live at yourdomain.com/llm.txt.
- Update Regularly: As new LLM providers emerge, keep your file up-to-date with new rules.
- Combine with robots.txt: While robots.txt focuses on search engines, it’s still useful alongside llm.txt for complete crawler control.
A Note on Enforcement
Right now, compliance with llm.txt is voluntary. Unlike robots.txt, which search engines like Google strictly follow, not all AI companies are guaranteed to respect llm.txt yet. However, with growing regulation (like the EU AI Act) and public scrutiny, enforcement mechanisms may soon be standardized.
If you're concerned about misuse, consider combining llm.txt with:
- Legal terms of service
- Copyright disclaimers
- Anti-scraping measures (like rate limiting or CAPTCHAs)
Final Thoughts
As AI continues to shape how we consume and create information, standards like llm.txt give power back to content owners. It’s a small file with a big impact—representing a cultural shift toward consent-driven data usage in AI.
If you run a website or publish content online, consider setting up an llm.txt file to clearly communicate your preferences. If you build AI tools, make sure your models respect those preferences.
Want to generate an llm.txt file easily?
Check out Keploy.io – our tools help developers build respectful, privacy-conscious AI systems and testing tools, including support for ethical crawling practices.
Read more on https://keploy.io/blog/community/llm-txt-generator