llms.txt Configuration Guide for AI Search 2026

llms.txt is an emerging standard that provides AI-specific instructions for how large language models should interact with your website. Placed at your domain root (/llms.txt), it complements robots.txt by offering context, preferred citation formats, and content guidelines specifically for AI systems. While not yet universally adopted, llms.txt is gaining traction as AI search grows. According to llmstxt.org, the standard aims to help website owners communicate directly with AI systems about their content preferences.

What is llms.txt? #

llms.txt is a proposed standard for communicating with AI systems:

• Location: yoursite.com/llms.txt
• Format: Plain text with structured sections
• Purpose: Provide context and instructions for AI
• Relationship to robots.txt: Complementary, not replacement

llms.txt Format #

A typical llms.txt file includes:

• Site description: What your site is about
• Content types: What content you publish
• Citation preferences: How you'd like to be cited
• Contact information: For AI-related inquiries
• Usage guidelines: How AI should use your content

Implementation Steps #

• 1Create file: Create llms.txt in your domain root
• 2Add site context: Describe your site and content
• 3Specify preferences: Citation format, usage guidelines
• 4Test accessibility: Verify file is publicly accessible
• 5Monitor: Check AI responses for compliance

Best Practices #

• Be concise: AI systems prefer clear, direct instructions
• Be specific: Vague guidelines are less effective
• Update regularly: Keep information current
• Complement robots.txt: Don't duplicate access controls

Limitations #

• Not universally adopted: Not all AI systems read llms.txt
• No enforcement: AI systems may not follow instructions
• Evolving standard: Format may change
• Limited impact: Content quality matters more

FAQ #

Is llms.txt required for AI search optimization? #

No. It's optional and emerging. However, it's low effort to implement and may provide future benefits as adoption grows.

Does llms.txt replace robots.txt? #

No. They serve different purposes. robots.txt controls crawler access; llms.txt provides context and instructions for AI systems.

Conclusion #

llms.txt is an emerging standard for AI-specific website instructions. While not yet universal, it's low effort to implement and positions your site for future AI search developments. Create a simple llms.txt file with site context, content descriptions, and citation preferences.

About the Author

Yue Zhu@Seenos.ai

Product Manager at Seenos.ai. Pioneer in AEO research since 2024, exploring the convergence of SEO and GEO (Generative Engine Optimization). Led multiple AI-powered content optimization projects that achieved 300%+ citation increases in ChatGPT and Perplexity.