Does your website need an llms.txt file? What it does and doesn't do
llms.txt won't lift your search rankings, but it does change what an AI agent understands about your business. Here's when to add one and what to put in it.
llms.txt is a plain text file that you put at the root of your website, next to robots.txt. Its job is to give a language model a short, clean description of what your site is and where the important pages are, so that the model doesn’t have to reconstruct that from your homepage’s navigation, hero images and cookie banner.
In 2026, an llms.txt file won’t improve your Google rankings, and it isn’t required by any of the major agent platforms. A lot of sites that have one also see no measurable effect from it. So why bother?
What it does
It does two things.
First, when an agent lands on your site to answer a question about your business, an llms.txt gives it a straight answer. “This is a family dental practice in Round Rock, Texas. Services and prices are here. Hours and booking are here. Insurance accepted is here.” An agent that reads that will report back accurately, whereas one that has to infer the same facts from a page built for humans sometimes gets them wrong. A wrong answer about your prices or your service area costs you the recommendation.
Second, it’s a signal that you’ve thought about agents at all. That’s not worth much on its own, but it’s cheap, and it’s the kind of thing that gets noticed when an agent, or a person building one, is deciding which businesses are easy to work with.
What it doesn’t do
It doesn’t replace structured data. Schema.org markup is what agents rely on for facts (prices, hours, availability), and it matters far more than llms.txt, so do that first.
It doesn’t control crawling either, because that’s the job of robots.txt. If you’ve blocked AI crawlers there, an llms.txt won’t undo it.
And it won’t get you indexed anywhere. No agent platform reads llms.txt files to build a directory, and the file gets used at the point when an agent is already looking at you.
The format
The convention is a Markdown file with a top-level heading for the business name, a one-line summary in a blockquote, and then sections of links, each with a one-line description. Here’s a minimal example for a service business:
# Womack Mechanical
> Residential HVAC repair and installation in Fort Worth, Texas.
> Family owned since 1994. Same-day service for most repairs.
## Services and pricing
- Repair (diagnostic fee and hourly rates): https://womackmechanical.com/repair/
- Installation and replacement: https://womackmechanical.com/install/
- Maintenance plans: https://womackmechanical.com/maintenance/
## Booking and hours
- Book online (real-time availability): https://womackmechanical.com/book/
- Hours, service area and emergency line: https://womackmechanical.com/contact/
## Policies
- Cancellations, deposits, warranties: https://womackmechanical.com/policies/That’s all there is to it. Keep the file short and keep it current, because an llms.txt that links to a pricing page you took down two years ago is worse than having none.
When to add one
Add it if any of these apply:
- Your homepage is built around images, video or a single-page app, and the key facts about your business aren’t in plain text near the top.
- You have prices, policies or service details spread across several pages, and you’d rather point an agent at the right one than have it guess.
- You’ve already done the structured data work and want a cheap extra.
Skip it for now if your site has no structured data and your prices are in a PDF. Fix those first, since they’re the things that agents actually stumble on.
One caution
Some agencies have started selling llms.txt as an “AI SEO” service. There’s nothing wrong with paying someone to write a good one, but if the pitch is that it will get you ranked in ChatGPT or found by Muse, that isn’t how it works. The file helps an agent that’s already looking at you. Getting agents to look at you in the first place is a different job, and we wrote up what that job involves.
If you want a second opinion on whether your site is readable to an agent, including whether your llms.txt says what you think it says, request a free assessment.
Find out what the assistants see when they look at your business
The assessment is free. A person checks where you stand in search and AI answers, runs the four agent checks (Find, Understand, Transact, Trust) and tries to book or buy, then emails you a one-page report with the three fixes we think matter most.