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llms.txt Explained: The File Every Website Needs in 2026

· REX Bunny
GEOTechnicalAI Search

What Is llms.txt?

llms.txt is a plain text file you place at your domain root (like robots.txt) that gives AI language models a structured summary of your website. It was proposed as a standard by the LLM and AI community and has been adopted by major AI crawlers including GPTBot, Claude-Web, and PerplexityBot.

Think of it as a business card for AI. When an AI crawler visits your domain, llms.txt is one of the first things it reads. Without it, the model has to parse your entire HTML structure to understand who you are and what you do. With it, you provide a clean, structured summary that the model can instantly consume.

Why It Matters

AI models need to understand four things about your business:

  • Who you are — Your company name, brand, and entity identity
  • What you do — Your products, services, and value proposition
  • What services you offer — A structured list they can reference in responses
  • How to describe you to users — The exact phrasing you want AI to use

Without llms.txt, the AI has to infer all of this from your HTML. With it, you control the narrative. If you don’t provide an llms.txt file, the AI might describe your business using outdated or incomplete information it found elsewhere on the web.

How to Create One

Create a file at https://yoursite.com/llms.txt with this structure:

# Your Company Name
> One-line tagline describing what you do

## About
2-3 sentences about your company, what you do, who you serve, and what makes you unique.

## Services
- [Service Name](https://yoursite.com/service): Brief description of the service
- [Another Service](https://yoursite.com/another): Brief description

## Key Pages
- [Pricing](https://yoursite.com/pricing): Link to pricing and plans
- [Case Studies](https://yoursite.com/portfolio): Real client results
- [Blog](https://yoursite.com/blog): Industry insights and guides

## FAQ
- **Question?** Answer.
- **Another question?** Answer.

Best Practices

  1. Keep it concise — 200-500 words maximum. AI models have token limits and prioritize brevity.
  2. Use Markdown — AI models parse Markdown easily. Headers, lists, and links are all understood.
  3. Include links — Point to your key pages so the AI can reference them in responses.
  4. Update regularly — Keep it current with new services, pricing changes, or product launches.
  5. Add an FAQ section — Questions and answers in llms.txt directly influence how AI describes your business.
  6. Reference it in robots.txt — Not required, but ensures compliant crawlers find it.

Common Mistakes to Avoid

  • Making it too long — More than 500 words gets truncated by some models
  • Using complex formatting — Stick to basic Markdown. Tables and nested lists may not parse correctly
  • Omitting your value proposition — The tagline (line starting with >) is the first thing AI reads
  • Not including links — Without URLs, the AI can’t direct users to your pages

Real Example

Here’s the current llms.txt we use for REX Bunny Services:

# REX Bunny Services
> Marketing Agency for SEO, GEO & AEO — Making your brand visible in every search.

## About
REX Bunny Services is a marketing agency specializing in SEO, GEO, and AEO.
We make brands visible in Google, ChatGPT, Gemini, Siri, Alexa, Perplexity, and Copilot.

## Services
- [SEO](https://rexbunnyservices.online/services/seo): Technical and local SEO
- [GEO](https://rexbunnyservices.online/services/ai-search-optimization): AI citation optimization
- [AEO](https://rexbunnyservices.online/services/aeo): Answer Engine Optimization
- [Web Dev](https://rexbunnyservices.online/services/web-development): High-performance websites

How llms.txt Relates to AEO

Your llms.txt is also a key component of AEO (Answer Engine Optimization). Voice assistants like Siri and Alexa may reference your llms.txt content when answering questions about your business. A well-structured llms.txt helps ensure the AI describes you correctly — whether in a text response or a spoken answer.

Want us to set up llms.txt for your site? Run a free audit and we’ll include it in your report.

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