What Is llms.txt?
The file that tells AI models what your website does — and why fewer than 5% of sites have one.
Definition
llms.txt is a plain-text markdown file placed at the root of your website that provides structured information about your product or service specifically for large language models.
Think of it as robots.txt for AI understanding. While robots.txt tells crawlers what they can and cannot access, llms.txt tells them what your site actually does, who it's for, and where to find more information.
It was proposed by Jeremy Howard (Answer.AI) in September 2024 and has been gaining adoption across developer tools, SaaS products, and documentation sites. Major AI providers are increasingly prioritizing pages that have this file when answering user questions.
Why You Need One
AI models prioritize it
When ChatGPT crawls two identical sites — one with llms.txt, one without — it has significantly better context about the one with it.
It's the easiest win
Creating an llms.txt takes about 10 minutes. Compare that to months of link-building for traditional SEO.
Almost nobody has one
Fewer than 5% of websites have implemented llms.txt. Early adoption gives you a significant visibility advantage.
It helps accuracy
Without llms.txt, AI models guess what you do based on page content alone. This leads to inaccurate descriptions and missed recommendations.
Format Specification
# Product Name (required — first line) > Optional blockquote summary of your product. ## Section Heading (optional sections) Content within sections... ## Links (recommended) - [Label](url): Description of what this link contains
The format follows standard markdown conventions. The H1 is your product name, the blockquote is a brief description, and H2 sections organize additional information.
Real Example: TopLLMlister's Own llms.txt
We practice what we preach. Here's what we have at topllmlister.vercel.app/llms.txt:
# TopLLMlister - llms.txt > Free AI-readiness checker. Scan your website against 8 signals LLMs look for. ## About TopLLMlister checks whether AI assistants can read and recommend your website... ## Features - Free AI-readiness scan: no signup required - 8-signal server-side check - Before/After toggle - Autopilot mode ## Links - [Website](https://topllmlister.vercel.app) - [Free Scan](https://topllmlister.vercel.app/check)