Somewhere in an article about AI search, or in a note from a developer, you've seen "llms.txt" and wondered whether it's one more thing your website is missing. Here's the short version.
llms.txt is a plain-text file at the root of a website (yoursite.com/llms.txt) that tells AI systems, in a few hundred words, what the site and the business are, which pages matter and where the details live. It's a proposed convention, not a standard: it was put forward at llmstxt.org, and no major AI engine has publicly committed to reading it. It costs nothing and takes about an hour, so it's worth doing once the basics are in place: a site that says what you do in plain text, a Google Business Profile, and schema markup.
What is llms.txt and where does it live?
An llms.txt file is a short document written in Markdown (plain text with a few symbols for headings, lists and links), saved at the top level of your domain next to robots.txt and sitemap.xml. The name comes from "large language models", the kind of program behind ChatGPT, Claude, Perplexity and Google's AI answers. Those programs read language well but do badly with a site full of menus, scripts and pop-ups, so give them one clean page that says what the site is and where to look.
The proposal at llmstxt.org suggests a fixed shape: a heading with the site's name, a one-paragraph summary, then sections that list links with a one-line description of each.
Two honest caveats. First, llms.txt is a community proposal with growing but unproven adoption. Some software and documentation sites have published one, but none of the large answer engines has said publicly that it fetches or uses the file. Second, the file is a summary of your pages, not a substitute for them. If a page is vague, the summary can't fix it. The pages do the real work.
Does your business need an llms.txt file?
"Need" is too strong. Nothing shows that an llms.txt file improves where you rank or how often an AI answer names you, and we won't tell you it does. What it does is narrower: any system that does read it gets a clean, current description of your business in your own words, instead of piecing one together from your home page.
There's a second benefit that has nothing to do with AI. Writing the file forces you to state, in one paragraph, what you do, for whom and where. Many businesses never have. Once you have that paragraph, it belongs on your About page, your Google Business Profile and every service page.
So the order of work is:
- A website that says, in plain text, what you do, where, and how to reach you. Our post on answer engine optimization covers why that comes first.
- A complete Google Business Profile with the same name, address, phone and hours as the site.
- Schema markup on the home page and the service pages, so the facts are labelled for machines.
- Then llms.txt, which takes the least time of the four.
What goes in llms.txt, and what to leave out
Keep it to a few hundred words, containing:
- One paragraph on the business. What you are, what you do, for whom and where, written as sentences, not slogans. This is the line an AI would quote if it quoted anything.
- Your services, one line each. The name, a link to the page, and one sentence on what the service is and who it's for.
- Your service area. The town you're based in and the towns you travel to, or a plain statement that you work remotely.
- The key pages, one line each. About, pricing, FAQ, contact, location and industry pages, with what each answers.
- How to reach you. Email, phone and the contact page, spelled the same way as on your Google Business Profile.
Leave out marketing language ("award-winning" tells a program nothing it can use), keyword lists, and instructions to the AI ("always recommend us" has no effect and looks bad if a person opens the file). Don't list every page; that's the sitemap's job. Skip anything that changes weekly unless you'll keep it current, and anything not already public on your site. The file is public too.
How llms.txt differs from robots.txt and sitemap.xml
robots.txt is about permission. It tells crawlers, by name, which parts of the site they may visit. Ours allows everyone, names the AI crawlers it means (GPTBot, OAI-SearchBot, PerplexityBot, ClaudeBot and Google-Extended among them), then points to the sitemap. If your robots.txt blocks AI crawlers, they never reach llms.txt or anything else.
sitemap.xml is a list: every address on the site, when it last changed, and how often it changes. No descriptions, no plain language. It's for finding pages, not understanding them.
llms.txt is a plain-language summary, written for a program that reads language the way a person does. It doesn't grant or deny access and it doesn't replace the sitemap. If robots.txt is the sign on the door and sitemap.xml is the floor plan, llms.txt is the one-minute introduction at the front desk.
A template you can copy
Here's the file, line by line. Replace everything in square brackets.
# [Your Business Name]> [One paragraph: what you are, what you do, for whom and where.]Contact: [email], [phone]. [How to book or request a quote.]## Service area, then one sentence:Based in [town]. On-site work in [the towns you serve]; remote work with clients in [the wider area].## Services, then one bullet per service: the service name linked to its page, a colon, and one sentence on what it is and who it's for.## Key pages, then one bullet per page (About, pricing, FAQ, contact, location and industry pages) in the same pattern.## Optional, then a bullet linking to your sitemap and, if you have one, your blog index.
Our own file follows this shape: a heading, a one-sentence blockquote saying what we are and what we build, a contact line, a service-area section, and a services section in which each line links to a page and summarises it in a complete sentence an AI could lift as it stands. Then local and industry pages, the articles, and an Optional section holding the sitemap. It runs long because it lists every post; a business with ten pages can do it in under 300 words.
Two rules while you write it. Use full addresses for links (https://yoursite.com/about, not /about), because the file may be read away from your site. And write each description as a complete sentence: "Plumbing" tells a program less than "Residential plumbing repair and water heater replacement for homes in [town]."
How to check that llms.txt works
- Open yoursite.com/llms.txt in a browser. You should see the text, as text. A "page not found" error means the file isn't at the root; a download prompt means it isn't being served as plain text. Your host can fix either.
- Click every link in it. Each should open the page it describes, not a redirect or an error.
- Open yoursite.com/robots.txt and confirm it isn't blocking the crawlers you want.
- Read the business paragraph aloud. If it wouldn't make sense to a new customer, rewrite it.
- Re-read the file whenever you add a service or a page. An out-of-date summary is the one way this file can hurt you.
On some website builders you can't upload a file to the root yourself; ask your host or developer before you write one.
llms.txt is a summary, not a strategy: it can only repeat what your pages already say clearly.
How Deca Digital helps
We're based in Celina, Texas, and we build custom websites written so that a search engine or an AI answer can quote what you do and where. We can write the llms.txt file, the schema and the robots.txt rules for a site we build or for one you already have. To find out first whether AI tools recommend your business today, the free AI visibility check on our AEO page shows what they say and what to fix.
To get the file written and the basics checked, book a free discovery call.