What is llms.txt, and do you need one?

4 min read. Published November 2026.

What it is

llms.txt is a plain text file in Markdown at yoursite.com/llms.txt. It lists your most important pages with a one-line description of each, so a language model can find what matters without crawling everything. Jeremy Howard published the proposal on September 3, 2024.

Does anyone read it?

As far as we know, no major AI search engine has said it uses llms.txt to decide what to cite. Google's John Mueller has said that none of the AI services have said they use it. Treat it as cheap preparation, not a ranking lever.

Why we still check for it

It takes ten minutes, it can't hurt, and it's ready if an engine starts using it. That's why it's a 2-point bonus in our grade, not a core check. 62% of the Fairfield County business sites we tested had none, and for most of them that's the least urgent fix on the list.

How to write one

# Your Business Name

> One sentence on what you do and where.

## Main pages
- [Services](https://yoursite.com/services): what you offer and prices
- [About](https://yoursite.com/about): who you are, service area
- [Contact](https://yoursite.com/contact): phone, hours, booking

## Optional
- [Blog](https://yoursite.com/blog): guides and updates

Keep it short and current. Link only public pages.

What it doesn't do

It doesn't allow or block anything. That's robots.txt's job, and your server's. If a crawler can't reach your site, llms.txt won't help. Check that first.