What Is llms.txt? What It Does, What It Does Not, and Our Own File

If you have read anything about "answer engine optimisation" lately, you have probably seen llms.txt. It is a small text file, and it comes with big claims. This guide explains what it is, shows the one we run, and gives an honest answer to the question people actually ask: does it work?

llms.txt is a proposal for a Markdown file that gives AI tools a short, curated summary of a website. The proposal was written by Jeremy Howard and published on llmstxt.org on 3 September 2024. The site describes the file as offering "brief background information, guidance, and links to detailed markdown files", so that an AI agent can get to the important pages without wading through everything.

It is a proposal, not a standard that every search engine or AI company has agreed to follow. That matters for the answer to "does it work?" below.

According to llmstxt.org, the file is Markdown, in this order:

• An H1 with the name of the project or site. This is the only required section.
• A blockquote with a short summary of the project.
• Optional detail: ordinary Markdown paragraphs or lists, without headings, that explain the project.
• H2 sections containing lists of links. Each item is a Markdown link, optionally followed by a note.

The proposal says the file can be placed at the site root or at any path within it. The usual place is /llms.txt on your own domain.

NullGlitch publishes one. It is generated by one route in our site, and its product list comes straight from our product data. Here is a shortened excerpt (the full file has more sections):

# NullGlitch

> NullGlitch builds honest software for small business owners in New Zealand: ...

## What NullGlitch is (and is not)

- IS NOT: a web development agency or digital agency. Web projects remain available but are secondary.

## Guides

- [Connecting AI to your business data with an MCP connector](https://www.nullglitch.co.nz/blog/mcp-connector-for-your-business): what an MCP connector is, why read-only by default matters, and the Invio Xero Connector as a worked example.

You can read the full, live version at nullglitch.co.nz/llms.txt. We also use it to say what we are not, for example that we are not a web agency, so an AI summary does not describe us wrongly. The product list builds itself from our product data; the guide links are added by hand when we publish a new guide.

Here is what the official sources say.

Google's guide to optimising for its generative AI features says: "You don't need to create new machine readable files, AI text files, markup, or Markdown" to appear in Google Search. It adds that creating and maintaining llms.txt files is completely fine, but doing so "will neither harm nor help your site's visibility or rankings in Google Search, as Google Search ignores them."

For Google's AI Overviews and AI Mode, its AI features documentation says: "There are no additional requirements to appear in AI Overviews or AI Mode, nor other special optimizations necessary." The page must be indexed and eligible to be shown in Google Search with a snippet, and there is "no special schema.org structured data that you need to add".

We looked for an official statement from an AI company saying its assistant reads llms.txt files from other websites, and did not find one. Some companies publish an llms.txt for their own documentation (Anthropic does, at platform.claude.com/llms.txt), but publishing one is not the same as reading yours. Several blogs claim specific AI tools use the file. We have not found that on an official page, so we do not repeat it.

• It is cheap: a few lines of Markdown and a route or file on your domain.
• It is a useful clean summary: writing one forces you to say in plain words what your business does and which pages matter. That alone is worth the hour.
• It is not a ranking lever: Google says it ignores the file, and we have no official evidence that other tools rely on it.
• It does not replace the basics: pages that are indexed, useful and clearly written are what get shown in AI answers and in search.

If the goal is to appear in search and in AI answers, the work that counts is dull and familiar. Make sure your pages are crawlable and indexed. Write pages that answer real questions better than the alternatives. Link them to each other. Keep contact details and business facts accurate. Check Search Console to see what Google has actually indexed.

That is what our SEO and AI search audit looks at. It is a fixed-price, written audit of how your site shows up in Google and in AI search, and it will tell you plainly if something like llms.txt is not worth your time.