llms.txt is a plain text file, written in markdown, that sits at the root of a website (yourdomain.ie/llms.txt) and tells AI tools what the site is, which pages matter and where to find them. It was proposed in 2024 as a convention, in the same family as robots.txt and sitemap.xml, and it is entirely optional. No large AI company has confirmed that its tools read it, but it costs nothing, takes under an hour, and is a useful exercise in writing your business down plainly.
That is the whole answer. The rest of this guide covers where the idea came from, what goes in the file, a skeleton you can adapt, and an honest view of whether it is worth your hour.
Where the idea came from
The proposal was published at llmstxt.org in September 2024 by Jeremy Howard, who runs the research group Answer.AI. His argument was simple. AI tools can only hold so much text at once, and a normal web page is mostly menus, scripts, cookie banners and footers. A short markdown file that says “here is what this site is, and here are the pages worth reading” gives a tool the shape of the site without the clutter.
It helps to see how it sits beside the files a website already has.
| File | Who it is for | What it says |
|---|---|---|
| robots.txt | Crawlers | Which parts of the site they may and may not read |
| sitemap.xml | Search engines | Every page address, with no description |
| llms.txt | AI tools | What the site is, and the important pages with a line on each |
| llms-full.txt | AI tools | The full text of the site in one markdown file |
robots.txt controls access. A sitemap is a list. llms.txt is the only one of the four written for a reader, which is why it is worth writing well.
What goes in it
The format is deliberately light. The only required part is a top level heading with the name of the business or site. After that, in order:
- A blockquote with a one line summary of what the site is.
- A few short paragraphs of plain detail, with no headings.
- Sections, each with a heading, containing a list of links. Each link has a title, the address, and a short description after a colon.
- An optional final section headed “Optional” for links a tool can skip if it is short on room.
For a small business, the detail paragraph is the valuable bit. Put the name exactly as it is on the sign, what you do, the town and Eircode, the areas you cover if you travel, the opening hours, a price range or “from” prices, the phone number and how to book. Write it like a good directory entry, not an advert. Nobody is persuaded by “passionate about hair” in a file meant for software.
Keep the links to the pages a customer would need: services and prices, hours and directions, booking, questions and answers. Five to ten links is plenty. The whole file should fit on one phone screen.
A skeleton you can adapt
Replace everything in square brackets. Every link should be a real page on your site.
# [Business Name]
> Independent [trade] in [Town], County [County], open six days a week and serving [nearby areas]. Walk-ins welcome, online booking available.
[Business Name] is run by [Owner] at [Street], [Town], [Eircode]. Open Tuesday to Saturday, 9am to 6pm, closed bank holidays. Prices start from €[amount] for a [service]. Phone [number]. Book online using the link below.
## Services and prices
- [Services](https://[yourdomain].ie/services): every service with a price
- [Gift vouchers](https://[yourdomain].ie/vouchers): bought online, sent by email
## Visiting
- [Hours and directions](https://[yourdomain].ie/contact): opening hours, bank holiday changes, Eircode and parking
- [Book an appointment](https://[yourdomain].ie/book): choose a service, a staff member and a time
## Questions
- [Frequently asked questions](https://[yourdomain].ie/faq): walk-ins, parking, children, cancellations and deposits
## Optional
- [About](https://[yourdomain].ie/about): who runs the business and since whenFor a live one, read halfpenny.ie/llms.txt. It is longer than a shop needs because it lists every guide and area page on this site, but the shape is the same: heading, summary, a paragraph of facts, then sections of links.
llms-full.txt
A companion convention grew up alongside the index file. llms-full.txt is the whole site’s text in one markdown document, so a tool can read everything in one go without following links. Mine is at halfpenny.ie/llms-full.txt and contains the pricing, the services, the questions and answers and every guide.
For a one location business with eight pages, the short file may be all you need. If you publish a lot, such as a clinic with a page per treatment or a restaurant with several menus, the full file saves a tool from having to find and read each page separately.
Does anyone actually read it?
Here is the honest position. The proposal has been adopted by a good number of software companies and documentation sites, and plenty of ordinary businesses have added one. What nobody has shown is that OpenAI, Google or Anthropic use it when answering questions. As we understand it, none of them has said their tools read the file, and Google has said it does not use it for search.
The only way to know whether your file is being fetched is to look at your server logs for requests to /llms.txt. Some owners see them, some do not. So the trade is an hour of your time against an unproven but harmless benefit, and the hour is not wasted even if the file is never read, because writing your facts down plainly usually shows up what is missing from the site itself. Our checklist of what a small business website should include is the place to take that list.
Do not pay anyone for “llms.txt optimisation”. There is nothing to optimise. The things that are known to matter for AI answers are a crawlable site, plain facts and consistent listings, which we cover in how to show up in ChatGPT answers.
How to put it on your site
It depends on how the site is built.
If the site is hand built or static, the file goes in the folder that holds robots.txt and favicon.ico, and it is live when the site is deployed. If the site is WordPress, upload it to the root folder by FTP or through your host’s file manager; some SEO plugins can now generate one for you. If the site is on a builder such as Wix or Squarespace, check whether the builder lets you place a plain text file at the root of the domain. Some do not, and the answer changes from year to year, so search the builder’s help pages before spending time on it.
Whichever way you do it, open yourdomain.ie/llms.txt on your phone afterwards. It should appear as plain text, with no login and no redirect, and your robots.txt should not block it. Save the file as UTF-8 so that euro signs and fadas survive.
Keep it true
A file that says you open at 9am after you moved to 10am does the opposite of what it is for. Treat llms.txt like the price list on your door: whenever hours or prices change on the site, change them here the same day. The best arrangement is to have the file generated from the same data as the pages, so it cannot drift. That is how the one on this site works: it is rebuilt every time the site is, from the same source as the pages.
What we do for clients
An llms.txt file is part of the AI search readiness that comes with Essentials, alongside structured data and question and answer content. We do not hand write it. It is produced from the same data as the site, so when an owner changes their hours or prices on their private edit page, the pages and the file update together.
We are clear with clients that this is a small, cheap piece of a bigger job, not a trick that gets a business into ChatGPT. The bigger job is the plain facts, the structured data, the matching listings and letting the crawlers in. What that looks like in practice is on the AI search page, and the plan it belongs to is on the pricing page.
Write an llms.txt file for your business: the steps
- Write the one line summary. One sentence that says what the business is, where it is and who it is for. It goes in a blockquote under the heading.
- List the facts that matter. A short paragraph of plain text: services, price range, opening hours, address with Eircode, phone number and how to book.
- Choose the pages worth linking. Pick the five to ten pages a customer would need: services, prices, hours and directions, booking, questions and answers. Skip the rest.
- Write it in the format. A top level heading with the business name, the blockquote, the facts paragraph, then sections with one link per line and a short description after a colon.
- Put it at the root of the domain. Upload it so it loads at yourdomain.ie/llms.txt as plain text. Open it on your phone to check.
- Keep it in step with the site. Whenever prices or hours change on the site, change them here too. A stale file is worse than none.