I want to be careful with this one, because there's a lot of overselling around it.

llms.txt is a proposal, published in late 2024, for a plain-text file at the root of a website — yourbusiness.com/llms.txt — that gives language models a concise summary of the site and a curated list of its most useful pages. Think of robots.txt, which tells crawlers what they may read, and sitemap.xml, which tells them what exists. llms.txt is the third file: it tells them what matters and what it means.

What it is not

It is not a standard that any AI company has publicly committed to reading. OpenAI, Anthropic, Google and Perplexity have all been quiet about it. It is not a ranking factor. Adding it will not, on its own, get you recommended, and anyone who tells you otherwise is selling a package.

So why is it a check in the Duly Noted audit, and why do I tell clients to add one?

The honest case

Three reasons, in order of weight.

First, it costs almost nothing and can't hurt. It's a text file. There's no downside beyond ten minutes.

Second, some retrieval systems do read it, and the number is growing. Developer tools and smaller answer engines adopted it early because it's convenient, and the convention has spread through the frameworks people build AI search on. When a crawler that understands it lands on your site, it gets a clean, curated summary instead of having to infer your business from a WordPress homepage full of navigation and sliders.

Third — and this is the real reason — writing it forces you to do something most businesses have never done: state, in two hundred words of plain text, what the business is, who it serves, where, and which five pages prove it. That summary is exactly the content your homepage, your schema description and your Google Business Profile should also carry, and in the process of writing llms.txt people usually discover that none of them do.

It's a low-weight check in the readiness score (three points) for precisely these reasons. It's on the list because the fix is trivial and the exercise is valuable, not because the file is magic.

The format

Markdown, which is to say plain text with a few conventions. One H1 with the business name. A blockquote with a one-paragraph summary. Optional short sections. Then a list of links, each with a one-line description.

# Saguaro Plumbing & Rooter

> Licensed, family-owned plumber serving Tucson, Oro Valley, Marana and Vail
> since 2009. 24/7 emergency service, drain cleaning, water heater repair and
> replacement, leak detection and repiping. Fixed-price quotes before work
> starts. Arizona ROC #000000.

## Services

- [Emergency plumbing](https://saguaroplumbing.example/emergency-plumber-tucson/): Same-day and after-hours response across Tucson; typical arrival under 90 minutes.
- [Water heater repair & replacement](https://saguaroplumbing.example/water-heaters/): Tank and tankless; installed prices listed.
- [Drain cleaning](https://saguaroplumbing.example/drain-cleaning/): Hydro-jetting and camera inspection; pricing by line.

## About

- [About Saguaro Plumbing](https://saguaroplumbing.example/about/): Owner, team, licensing and insurance.
- [Frequently asked questions](https://saguaroplumbing.example/faq/): Costs, timing, service area, permits.
- [Contact](https://saguaroplumbing.example/contact/): Phone, address, hours, map.

That's a complete file. Notice it repeats the facts that matter — service, place, credentials — and nothing else.

The ten-minute version

Open a text editor. Write the H1 and the summary paragraph; if you struggle with the paragraph, that's the useful discovery I mentioned, and the version you land on should go in your schema description too. List your five to eight most important pages with a sentence each. Save as llms.txt, plain text, UTF-8.

Upload it to the root of your site — the same folder as robots.txt. On WordPress that's usually via your host's file manager or FTP; some SEO plugins now offer to generate it and a couple of dedicated plugins exist. Confirm it loads at yourbusiness.com/llms.txt and that it comes back as text, not an HTML 404 page dressed up as a file.

Then, optionally, add a line to robots.txt pointing at it, the way you would a sitemap. It isn't standard, but it's harmless and some crawlers pick it up.

When it matters more

If your site is large — a multi-location business, an ecommerce catalogue, a firm with dozens of practice areas — llms.txt becomes more useful, because the curation is doing real work. A crawler that can read your two hundred pages has no way to know which twelve define the business. You do.

There's also a companion convention, llms-full.txt, that holds the full text of your key pages in one file. For a local service business it's overkill. For a site with documentation or long reference content, it's worth a look.

The honest summary

Add it. Spend the ten minutes. Then spend the next hour making sure your homepage and schema say the same thing the file does, because that consistency — not the file itself — is what the assistants reward.