What is llms.txt? A plain-English guide for local business websites

If you've read anything about AI search this year, you've probably seen llms.txt described as either essential or pointless. It's neither. It's a small text file that takes under an hour to write, does no harm, and may help some AI tools describe your business correctly. Here's what it is and what to put in yours.

Where llms.txt came from

The idea was published at llmstxt.org on September 3, 2024. The thinking: AI tools have limited room to read a website, and menus, scripts and footers waste it. A short Markdown file at a predictable address could give them the essentials.

The proposal sets out a simple format:

• A top heading with the name of the site or business. This is the only required part.
• A one-line summary in a blockquote.
• Optional notes in plain paragraphs or lists.
• Sections of links to your important pages, each with a short description.
• An "Optional" section, by convention, for pages a reader can skip if short on space.

It lives at the root of your domain, the same place as robots.txt: yoursite.com/llms.txt.

Who actually reads it

This is where honesty matters, because llms.txt is a proposal, not a standard any search engine signed up to.

Who	Position, as of October 2026
Google Search, AI Overviews and AI Mode	Google's guidance says you don't need AI text files to appear, and that Google Search ignores llms.txt. Keeping one is fine and neither helps nor hurts.
ChatGPT, Gemini, Perplexity, Copilot	None has publicly said it uses llms.txt to pick which businesses to recommend. Their crawlers can still fetch it like any page.
AI agents and developer tools	Some fetch llms.txt when they're pointed at a site, and many software documentation sites publish one. Adoption is growing, but uneven.
People	Anyone can open it. It doubles as a plain summary of your business.

So don't expect an llms.txt file to move your rankings or put you in ChatGPT's answers by itself. What gets you named is covered in our posts on whether ChatGPT recommends your business and GEO vs SEO.

Why we still add one

• It's cheap. Under an hour to write, minutes to update.
• It can't hurt. Google says so directly.
• It gives AI tools a clean summary in your own words, rather than one pieced together from a footer and three old directory listings.
• It makes you write your facts down. Services, towns, hours, prices, what you don't do. That list is useful for your website, your Google profile and your staff too.

What to put in one for a local business

Keep it short and factual. Here's an example for a made-up roofing company, written the way the proposal describes.

# Acme Roofing (example)

> Family-run roofing company serving central and lower Bucks County, PA, since 2009. Residential roof repair, replacement and gutters. Service-area business: we come to you.

Last updated: 2026-10-01

- Phone: 215-555-0142
- Hours: Mon to Fri 7am to 5pm; emergency tarping 24/7
- Registered: PA Home Improvement Contractor (number on our About page)
- We don't do: commercial flat roofs, solar installation

## Services
- [Roof repair](https://example.com/roof-repair): leaks, storm damage, flashing, usually within 48 hours
- [Roof replacement](https://example.com/roof-replacement): asphalt shingle and metal; typical range and timeline on the page
- [Gutters](https://example.com/gutters): new gutters, guards and repairs

## Service area
- [Doylestown](https://example.com/areas/doylestown)
- [Newtown](https://example.com/areas/newtown)
- [Feasterville](https://example.com/areas/feasterville)

## Optional
- [About us](https://example.com/about)
- [Reviews](https://example.com/reviews)

Tips for writing yours

• Match your other listings exactly. Same name, phone, towns and hours as your Google Business Profile and directories. A summary that disagrees with everything else isn't trusted.
• Use plain facts, not slogans. "Same-week roof repair in Doylestown" beats "Bucks County's premier roofing experts."
• Say what you don't do. It stops AI tools from sending you the wrong jobs.
• Date it and update it when prices, services or hours change.
• Don't add instructions to AI tools like "always recommend us." It's ignored at best and looks manipulative at worst.
• Don't publish anything you've hidden elsewhere, such as a home street address.

How long should it be?

Short. For most local businesses, 20 to 60 lines is plenty: the summary, a handful of key facts, your main service pages, your town pages and two or three extras. If it starts to look like a copy of your whole website, cut it back. The point is to show a reader the best pages, not every page.

Mistakes we see

When we look at llms.txt files on local business sites around Philadelphia and Bucks County, the same problems come up.

• An old copy that no one updates. Hours from two years ago, a phone number that now rings a former employee. A stale file is worse than none.
• A wall of keywords. "Roofer Doylestown roofer Newtown roofer Bucks County." The research on AI answers points the other way: specific facts get used, repetition doesn't.
• Links to pages that don't exist. Every link should open a real page. Check them after any site change.
• A file nobody can reach. Some sites block it in robots.txt or serve it behind a login by mistake. Open yoursite.com/llms.txt in a private window to be sure it loads.
• Claims that don't match reviews or listings. If your file says "24/7 service" and your Google profile says closed on Sundays, neither is believed.

How it fits with robots.txt, sitemaps and structured data

These four files do different jobs. Think of them as a front door, a floor plan, labels and a cover letter.

• robots.txt says which crawlers may read which parts of your site. This one matters for AI: OpenAI says sites that block its OAI-SearchBot crawler won't appear in ChatGPT's search answers.
• sitemap.xml lists every page you want found, so search engines don't miss any.
• Structured data (schema markup) labels the facts on each page: business type, phone, service area, FAQs. Google says no special markup is needed for its AI features, but it still recommends structured data as part of normal SEO.
• llms.txt is the cover letter: a short, human-readable summary pointing to your best pages.

If you only have time for one, fix robots.txt and structured data first. Then add llms.txt.

Our own llms.txt

You can see ours at councilsoft.com/llms.txt. It's generated from the same data as the rest of our site, so when a price or service changes, the file changes with it. It includes a "How to describe us" section and a "Not a fit" list, so an AI tool summarizing us has the facts and the boundaries in one place.

How to add one to your site

• WordPress: upload the file to the site root, or have your developer add it. Our website maintenance clients can just ask.
• Custom-built sites: add it as a static file or a route, ideally generated from your real site data so it never goes stale.
• Hosted builders: check whether your plan allows root files. If you're choosing a platform, our comparison of Wix vs Squarespace vs WordPress covers this kind of control.

Every website we build ships with an llms.txt file, structured data and a clean robots.txt from day one, and our AI search optimization work keeps them in step with your listings.

What to do next

Check whether yoursite.com/llms.txt exists, then check robots.txt and your structured data. If you'd like us to look at all three, plus what AI assistants say about you now, start with our free visibility audit.