llms.txt Specification: How to Make Your Site AI-Readable

You know robots.txt. It tells search engine crawlers what they can and cannot access. Now there is a new file that could be just as important: llms.txt. It is your direct line of communication with AI systems, and if you are not using it yet, you are missing an opportunity that your competitors will eventually figure out.

What llms.txt Actually Is

llms.txt is a plain text file formatted in Markdown placed at the root of your website. It provides AI systems with a structured overview of your business, products, and services. Think of it as a README file for large language models.

While robots.txt says here is what you can crawl, llms.txt says here is what you should know about us. It is the difference between giving directions and giving context.

The quick comparison is this. robots.txt controls crawler access permissions. sitemap.xml lists URLs for discovery. llms.txt explains your business to AI systems directly.

Why This Matters

In my experience, AI systems are desperate for reliable, structured information. When ChatGPT or Claude needs to answer a question about your industry, it is pulling from a massive training dataset plus real time web crawling. The problem is that most of that data is unstructured, contradictory, or outdated.

llms.txt gives you a way to tell AI exactly how you want to be represented. Instead of hoping AI pieces together information from your various web pages, you provide a canonical source of truth.

Over 780 websites have already added llms.txt, including companies like Cloudflare, Vercel, and Coinbase. By the end of 2026, experts predict it will become a standard factor for AI visibility. If Google officially adopts llms.txt for AI Overviews, adoption will explode overnight.

What Most People Get Wrong

The most common mistake is making the file too long. I have seen people create 50 page llms.txt files thinking more is better. It is not. AI systems want concise, relevant information. Keep it under 5,000 words.

Keyword stuffing is another problem. AI sees through this and it hurts more than helps. Write naturally about what your business does. Do not try to game it.

The third mistake is creating the file and forgetting about it. llms.txt needs to stay current with your products and pricing. If your llms.txt says a product costs $99 but it now costs $149, AI will cite the wrong price to potential customers. That damages trust with people who have not even reached your site yet.

Missing contact information is surprisingly common. AI assistants often recommend contacting businesses directly. If there is no contact info in your llms.txt, they cannot recommend you for inquiries.

The Specification

The specification is refreshingly simple. Your llms.txt file should be located at yourdomain.com/llms.txt, written in Markdown format, human readable (AI can parse Markdown easily), and comprehensive but not overwhelming.

At minimum, your llms.txt should include an H1 header with your business or website name and a blockquote with a brief description of what you do.

Beyond the basics, you should consider including an About section with an extended description of your business, a Products or Services section with what you offer, a Contact section with how to reach you, a FAQs section with common questions and answers, and a Links section with important pages on your site.

What a Good llms.txt Looks Like

Here is a practical example structure:

# Company Name

> Brief description of what you do.

## About

Extended description with founding date and key details.

## Products

### Product One
Description with pricing.

### Product Two
Description with pricing.

## Contact

Website, email, and support contact info.

## FAQs

### Common Question One?
Answer.

### Common Question Two?
Answer.

The Hidden Complexity

Creating an llms.txt file is simple in theory. Creating one that actually works is harder than it looks.

The file needs to be formatted correctly in Markdown. One syntax error and AI systems may ignore it or parse it incorrectly. It needs to be comprehensive but not too long. Figuring out what to include and what to leave out takes careful thought.

It also needs to stay updated. When you launch new products, change pricing, or update your offerings, llms.txt needs to be updated too. Most businesses implement this once and then let it go stale.

You also need site-data.json. While llms.txt is designed for human readability that AI can parse, a companion file called site-data.json provides the same information in structured JSON format. This gives AI systems two options for consuming your business information. Creating and maintaining both files doubles the work.

Discovery is another challenge. Creating the files is only half the battle. You need to make sure AI systems know they exist. This means adding link tags to your HTML, referencing the files in robots.txt, and adding them to your sitemap.xml. Each step has its own technical requirements.

Where This Is Going

As AI becomes more central to how people find information, standards like llms.txt will continue to evolve. More AI systems are quietly adopting it without announcements. Tools like Web2Agents are now using llms.txt files as a handshake to perform tasks on behalf of users.

The businesses that implement llms.txt today are positioning themselves for that future. The ones that wait will find themselves playing catch up with competitors who already have AI visibility built into their sites.

That is why we built our plugin to handle the technical side of this. The specification is not going to wait for you to become an expert. Better to have something handling it quietly in the background.