llms.txt: What It Is and Whether Your Site Needs One

Short answer: llms.txt is a plain Markdown file at the root of your site, such as example.com/llms.txt, that gives AI assistants and agents a short summary of your business and links to your most useful pages. As of November 2026, Google Search says it doesn't use llms.txt for rankings or its AI features, while Chrome's Lighthouse checks for one in its agentic browsing audits. For a small business site it's a 15-minute, low-risk extra, not an SEO lever, so write one only after your actual pages are clear and well structured.

Where it came from

The proposal lives at llmstxt.org. It was first written in 2024, when the authors expected AI agents to start reading websites to answer questions. The current version (v2) says that has become routine: coding agents read documentation, chat assistants read product pages.

The problem it tries to solve is simple. Web pages wrap their information in menus, cookie banners, scripts and layout. A language model has limited context, and every wasted token costs time and money. llms.txt offers a curated, compact entry point instead.

The v2 page notes that thousands of sites publish one, documentation platforms generate them automatically, and AI labs publish llms.txt files for their own developer docs. Its main use has been software documentation, but the proposal explicitly mentions businesses outlining their structure and policies.

What goes in the file

The spec is short. In order:

An H1 with the site or project name. This is the only required part.
A blockquote with a short summary containing the key facts.
Optional paragraphs or lists with more detail (no headings).
Optional H2 sections containing lists of links, each written as [name](url): optional note.
By convention, an "Optional" H2 section for secondary links an agent can skip.

The proposal also suggests offering clean Markdown versions of important pages (for example page.md next to page.html) and pointing to them from the file. That second part is more work and mostly relevant to documentation sites.

It isn't robots.txt. robots.txt tells crawlers what they may access; llms.txt tells an agent what is worth reading. And it isn't a sitemap, which lists everything; llms.txt is a short, hand-picked guide.

What Google and Chrome say (as of November 2026)

The two Google teams take different angles, which has confused a lot of people.

Google Search: its guide to generative AI features lists llms.txt under things you can ignore. You don't need new machine-readable files, AI text files or Markdown to appear in Google Search, including its generative AI capabilities, "as Google Search itself doesn't use them". Google may still crawl such a file like any other, but that doesn't mean it's treated specially.

Chrome Lighthouse: its agentic browsing audits include an llms.txt check. If the file returns a 404, the audit is marked not applicable, "as providing the file is optional at the moment". A server error fails it. Chrome's documentation says that without the file, agents may spend more time crawling to understand a site's structure.

So the file has no Google ranking value, and some value for AI agents that browse sites on a user's behalf. Whether other AI assistants read it when answering questions varies by product, and most don't publish clear statements. We couldn't verify any major assistant committing to use it for answers about local businesses.

A sample llms.txt for a small business

Here's a hypothetical example for a physiotherapy clinic. Keep it factual and current; anything you write here may be quoted.

# Harbourside Physio

> Physiotherapy clinic in Wellington, New Zealand. Sports injuries, back and neck pain, post-surgery rehab. Open Monday to Saturday. ACC-registered. Online booking available.

- Address: 12 Example Quay, Wellington 6011
- Phone: +64 4 000 0000
- New patients: book online or call; no referral needed for most treatments.

## Services
- [Sports injury physio](https://example.co.nz/sports-injuries): assessment, treatment plans, return-to-sport testing
- [Back and neck pain](https://example.co.nz/back-neck-pain): what to expect at a first visit
- [Post-surgery rehab](https://example.co.nz/rehab): knee, hip and shoulder programmes

## Booking and prices
- [Book an appointment](https://example.co.nz/book)
- [Fees and ACC](https://example.co.nz/fees): current fees and what ACC covers

## Optional
- [About the team](https://example.co.nz/team)
- [Blog](https://example.co.nz/blog)

How to publish it in 15 minutes

Write the file in any text editor and save it as llms.txt (UTF-8).
Upload it to your site's root so it loads at /llms.txt. On WordPress, a file manager or an SEO plugin feature can do this; on hosted builders, check whether they allow root files.
Open the URL in a browser and confirm it shows as plain text, not a 404 or an error page.
Add a calendar reminder to update it when prices, hours or services change. An outdated llms.txt is worse than none.

Verdict

Do it if you've already got clear service pages, accurate opening hours and contact details, and structured data in place, and you want one more low-cost signal for AI agents. Fifteen minutes is a fair price.
Skip it for now if your site's basics are weak. An agent that follows your llms.txt to a vague service page still gets a vague answer. Fix the pages first; our guide on writing service pages AI assistants can quote covers that.
Never expect it to change Google rankings. Google says plainly it doesn't use it.

FAQ

Can llms.txt block AI companies from training on my content?

No. It's a guide, not an access control. To limit crawling, use robots.txt rules for specific AI crawlers, knowing that compliance depends on each crawler.

Should I list every page?

No. The point is curation. List the ten or twenty pages that answer what customers actually ask.

Is there an llms-full.txt?

Some sites publish a longer file with the full text of key pages. The core spec focuses on llms.txt plus optional Markdown versions of pages; for a small business, the short file is enough.

Will an llms.txt hurt my site?

Not if it's accurate. The risk is stale information, such as old prices or hours being repeated by an AI assistant.

If you'd like help tidying your service pages and adding an llms.txt in the same pass, drop us a line.