llms.txt and llms-full.txt
llms.txt and llms-full.txt are text files (usually with markdown formatting) that contain information about various large language models (LLMs). Such an idea is not new; we had other indexing-related files like robots.txt or sitemap.xml. This is useful for LLM agents when reading websites more effectively.
I asked Claude Code about it:
Prompt:
what is llms.txt and llms-full.txt?
I got:
llms.txt
A concise navigation guide for AI models containing:
- Project/site name (required H1 header)
- Short summary in blockquote format
- Structured hierarchy of important content
- Links to markdown files with detailed information
- Suggestions for essential vs optional content
Uses Markdown format specifically because LLMs read it well.
llms-full.txt
A comprehensive single file containing all documentation content directly, eliminating the need for navigation across multiple files.
Purpose
These files live at the root (/llms.txt and /llms-full.txt) to help LLMs:
- Quickly understand what a project/site is about
- Navigate to relevant information efficiently
- Access complete documentation in one place
Examples across the internet: