llms.txt Explained: Do You Actually Need One?

Every few months a new file appears in the advice columns, and llms.txt is the current one. Some people describe it as essential for AI visibility. Others dismiss it. The accurate position is in between, and knowing it saves you from both wasted effort and unnecessary worry.

What it is

llms.txt is a proposal for a plain text file, written in Markdown, placed at the root of a website. It gives language models a concise, curated guide to your site: a short description of what you do, followed by links to the most important pages with a line about each. The idea is that a model with limited reading capacity can find your best material without parsing complex navigation and scripts.

What it is not

It is not an official web standard, and it is not a ranking factor that major search engines have confirmed. It does not control access the way robots.txt does, and it does not replace your sitemap. Several AI companies have not stated that they use it when producing answers, so any claim that it guarantees AI citations is unsupported.

Who might benefit

The file is most plausible for sites with a lot of documentation or reference material, where tools that read content on behalf of developers and users may find a curated map helpful. Software documentation, API references and large knowledge bases are the common examples. For a small service business with a handful of pages, the effect is likely small.

How to write one

If you decide to publish it, keep it short and honest:

1. Start with a title and a one or two sentence summary of your organisation.
2. List your most important pages as links, grouped under simple headings.
3. Add a short description after each link.
4. Keep it current. A stale file is worse than none.

Serve it as plain text at yourdomain.com/llms.txt.

What a simple file looks like

A minimal file has a title line, a one or two sentence summary, then headed lists of links. For a software company it might group links under headings such as documentation, guides and pricing. For a services business it might group them under services, about and contact. Each link has a short description so a reader, human or machine, knows what is behind it without opening it.

Write it as you would brief a smart colleague who has ten minutes to learn your business. Include the pages you would send them, and leave out everything else.

The reasonable position on the evidence

The honest summary is that the file is cheap, harmless and unproven. If you have the time, publishing one costs little and may help tools that choose to read it. If you do not have the time, nothing in the available evidence suggests that skipping it will cost you your visibility. Beware of anyone selling it as a breakthrough.

Use a simple rule. Publish it after you have fixed the things with known benefits, and treat any effect as a bonus. Watch announcements from the AI companies, because support could change either way.

Keeping it accurate

The worst version of the file is an outdated one that points to deleted pages. Add it to the same review routine as your sitemap. When you add a major page or retire an old one, update the file. If you cannot commit to keeping it current, do not publish it.

Where to spend effort first

Before creating the file, make sure the basics are in place. Your pages should be crawlable, your robots.txt should not block the assistants you care about, and your content should answer real questions clearly. Our robots.txt guide and readiness checklist cover those. The Search Readiness Auditor reports whether you have an llms.txt file and treats it as optional, because that matches the evidence.

Frequently asked questions