What Is an llms.txt File? A Plain-English Guide for Service Business Owners

If you've been hearing about llms.txt files and wondering whether your website needs one — you're not alone. It's new, it sounds technical, and most of what's been written about it reads like it was written for developers, not business owners.

This guide fixes that. Plain terms only. We'll tell you exactly what it is, what it doesn't do (just as important), and what you should actually do about it.

The short version — what is it, exactly?

An llms.txt file is a small, plain-text file you place on your website that gives AI tools a clean, organized summary of your business. Instead of forcing an AI to dig through your entire website — reading navigation menus, cookie banners, footer links, tracking scripts, and everything else a normal website contains — it hands the AI a curated briefing: here's who we are, here's what we do, here are the most important pages.

Think of it as a welcome packet for AI. The file sits at yourdomain.com/llms.txt, the same way your robots.txt file lives at yourdomain.com/robots.txt. It's a text file. It requires no software. It doesn't affect how your website looks or works for human visitors at all.

Why does this exist — what problem does it solve?

When an AI tool tries to understand your website, it has to read the actual HTML code — the raw source behind every page. That code is messy. A typical service page contains 2,000 words of useful content buried inside 15,000 or more lines of code: navigation, headers, footers, JavaScript, image tags, schema markup, tracking pixels, and everything else that makes a website work visually.

The AI has to guess what matters. Sometimes it guesses right. Sometimes it doesn't — and that's when you get inaccurate descriptions of your business, missing services, or a competitor getting cited instead of you.

Jeremy Howard — co-founder of Answer.AI and one of the most respected AI researchers working today — proposed llms.txt in September 2024 specifically to address this. The idea: give AI a clean, readable version of your site and it can represent your business accurately, quickly, and consistently — without having to reverse-engineer your website every time.

How it's different from robots.txt and your sitemap

These three files often get confused. They serve completely different purposes:

None of these replace the others. They work alongside each other. You still need your sitemap for Google. You still need your robots.txt. The llms.txt is a separate file for a separate audience — one that's growing fast.

Which AI tools actually read it right now?

Here's where we're going to be straight with you — because a lot of content about llms.txt isn't.

As of early 2026, no major AI platform has officially confirmed they read llms.txt in production. Google has explicitly stated they won't use it. One independent researcher tracked over 62,000 AI bot visits to their site and found that only 84 of them — less than 0.1% — actually accessed the llms.txt file.

So why does it still matter? Because the direction of travel is clear. AI search is growing. The tools that don't have a standardized way to read websites today will need one as the problem scales. A proposal backed by one of the most credible researchers in AI — and now adopted by over 844,000 websites including Anthropic (the company behind Claude) for their own documentation — carries more weight than most "new SEO tactics" that circulate online.

The practical calculation: implementation takes under an hour with free tools, costs nothing, and requires no ongoing maintenance beyond occasional updates. That's a reasonable investment for something that may matter a great deal in the near future — and does no harm in the present.

What actually goes inside an llms.txt file

The format is deliberately simple — plain text written in Markdown, a lightweight system that both humans and AI can read without any software. You don't need to know how to code to understand it or maintain it.

Here's what a complete llms.txt looks like for a local excavation company:

# Thompson Excavation

> Full-service excavation contractor serving Greater Calgary.
> Specializing in residential site prep, basement excavations,
> utility trenching, and lot clearing. Licensed, insured, 18 years operating.

## Services
- /services/site-preparation.md  Residential and commercial site preparation
- /services/basement-excavation.md  Basement excavations, underpinning, waterproofing prep
- /services/trenching.md  Utility and drainage trenching services
- /services/land-clearing.md  Lot clearing, grubbing, rough and finish grading

## About
- /about.md  Company history, owner profile, licensing, and insurance
- /equipment.md  Equipment fleet and project capacity

## Service Area
- /service-area.md  Service map, municipalities and communities covered

## Contact & Booking
- /contact.md  Phone, email, and project inquiry form

## Optional
- /faq.md  Common questions about excavation projects and timelines
- /blog.md  Project case studies and site preparation guides

The # is the business name. The > lines are a brief description of the business. Each ## is a content section. The dashes are links to the pages within that section, with short descriptions telling the AI what each page covers.

The Optional section at the bottom has a specific meaning: content listed there can be skipped by AI when context is limited. Use it for secondary content like blog posts and FAQs — things that add colour but aren't essential to understanding what you do.

llms.txt vs. llms-full.txt — what's the difference?

Two companion files often come up together. They serve different purposes:

For most local service businesses, start with llms.txt. If your business has extensive service documentation — detailed specs, multiple service lines, complex processes — add llms-full.txt as a companion. Both can coexist on the same site.

Does your business actually need one?

Probably yes — but let's be precise about why.

You don't need an llms.txt because it will immediately increase your traffic. It won't — at least not in any measurable way right now. You need one because of where things are heading, and because the cost of having one is essentially zero while the cost of being unprepared if AI search standardizes on this file format could be real.

Local service businesses are already watching search behaviour shift. People are asking ChatGPT "who's the best plumber in my area" or "what does site prep for a basement excavation actually cost." The AI answering those questions is forming impressions of your business based on what it can find and understand. Making your site easier to understand is a sensible move regardless of whether llms.txt becomes a formal standard.

How to get yours set up — step by step

This is simpler than it sounds. You have two routes: use a free generator, or have someone set it up properly as part of a wider site review. Here's the full process either way:

What a properly set-up llms.txt actually includes

Use this as a quality check against anything you produce — whether with a generator or manually:

• Accurate business name — exactly as it appears everywhere else online
• Clear business description — what you do, where you do it, who you serve
• All active service pages listed — not just your main services page, but individual service pages where they exist
• Service area or location information — the specific areas, cities, or regions you cover
• About or credentials page — years in business, licensing, affiliations, anything that signals authority
• Contact and booking path — how a prospect takes the next step
• Secondary content in the Optional section — blog, FAQ, testimonials listed but not prioritized
• No outdated pages or services — nothing listed that no longer exists or doesn't reflect how you work
• Accurate descriptions for each link — a one-line summary that tells the AI what the page actually covers