llms.txt: What It Is, and What We've Seen It Do on Real Sites
llms.txt is a plain-text file that sits at the root of your website and gives AI assistants a structured summary of your business: what you do, what it costs, how to reach you. Think of it as a sitemap for language models. Instead of letting ChatGPT or Perplexity piece your business together from scattered pages, you hand them one clean page of facts. We add the file to every site we build. Here is exactly what we put in it, plus a generator that writes yours in about a minute.
Why would you want one?
When an AI assistant answers a question about a business, it works from whatever it can find: the homepage, an old directory listing, a review from three years ago. Sometimes that picture is accurate. Often it is not. This file fixes the problem at the source. It lives at yoursite.com/llms.txt, it is written in simple Markdown that both humans and machines can read, and it lays your business out the way you would explain it to a new customer.
The short file and the full file
There are two flavours, and they do different jobs:
- The short version is a scannable table of contents. Business name, a one-line description, and links to the handful of pages that matter, each with a one-line note.
- The full version (llms-full.txt) is the everything file. Plans and pricing, the complete FAQ, contact details, all expanded in place so an assistant never has to follow a link to get an answer.
Start with the short one. Add the full version once the short one is stable and you have a habit of keeping it current.
What do we put in ours?
On aphyx.live, and on every client site we build, the file carries five sections:
- What we do: links to the main service pages, each with a one-line description.
- Pricing summary: mirrors the live pricing page, never a separate copy that can drift.
- Case studies: two or three, with the outcome stated in the link note.
- Recent articles: the newest posts, so assistants can see the site is alive.
- Contact: email, phone and WhatsApp.
That structure came out of trial and error on live sites, not a spec sheet. Which brings us to the rules.
The maintenance rules we learned the hard way
Link only canonical URLs. Never point the file at a redirect. An assistant that follows a redirect chain can end up citing the wrong address, or dropping the page entirely. Every link goes straight to the final URL.
Keep pricing synced to the live pricing page. AI engines cite the file as truth. If the file says one price and your pricing page says another, every AI that reads it misquotes your business to every customer who asks. We update both in the same edit, on the same day.
Stamp it with a last-updated date. It costs one line, and it tells both engines and humans how fresh the file is.
AI engines cite the file as truth. A stale price in it means every assistant misquotes your business.
Want one for your own site? Fill in the form below and it writes the file for you. Copy the output, save it as llms.txt, and upload it to your site root.
llms.txt Generator
Enter your business details and get a ready-to-save file. Nothing is sent anywhere; it all happens in your browser.
Upload it so it loads at yoursite.com/llms.txt. Update it whenever your pricing or offerings change.
Does it actually work?
Here is what we can honestly say. In the server logs of our own sites, AI crawlers do fetch these files. That is a first-hand observation from sites we run, not an industry statistic. Our free audit tool checks whether a site has the file, and most Singapore SME sites we scan do not.
And the plain caveat: llms.txt is an emerging convention, not a ratified standard. No major engine has formally committed to reading it, and adoption varies. But the file takes twenty minutes to create, costs nothing to host, and the downside of skipping it is that AI assistants keep guessing about your business. We treat it as cheap insurance, not magic.
For the bigger picture on how AI assistants choose which businesses to mention, start with our full guide to AI SEO and GEO, then read how to get your business found on ChatGPT.
Frequently asked questions
Do all AI engines read llms.txt?
No. Adoption varies across engines, and none of the major ones have formally committed to it. What we can say from our own server logs is that some AI crawlers do fetch the file from our sites today. The cost of having one is near zero, so we treat it as cheap insurance rather than a guarantee.
Where does the llms.txt file live?
At the root of your domain: https://yoursite.com/llms.txt. It is a plain-text file written in simple Markdown, so anyone can open it in a browser and read it. If your site has the more detailed companion file, that one sits at /llms-full.txt in the same place.
What is the difference between llms.txt and robots.txt?
robots.txt is about permissions: it tells crawlers which parts of your site they may or may not visit. llms.txt is about meaning: it summarises what your business does so AI assistants can describe you accurately. They do different jobs and work well together, so keep both.
How often should I update llms.txt?
Whenever your pricing or offerings change, update the file the same day, because AI engines treat it as a source of truth. A stale price in the file means every assistant that reads it misquotes your business. Beyond that, put a monthly check in your calendar and refresh the last-updated date.
Does llms.txt improve my Google rankings?
Not directly. Google ranks pages using its own index and signals, and this file plays no part in that. It is written for AI assistants like ChatGPT, Claude and Perplexity, which answer questions rather than list links. Treat it as part of your AI visibility work, alongside normal SEO rather than instead of it.
Written by the Aphyx team · Published 20 August 2026 · Last updated 20 August 2026
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