llms.txt explained: what it is and whether your site needs one

llms.txt is a plain-text (Markdown) file placed at the root of your website, at /llms.txt. It was proposed as a way to give large language models a concise, curated guide to your site: what it is, and where the most useful pages are, without wading through navigation, ads and scripts.

The idea behind it

Websites are built for people using browsers. For a language model reading a page, much of that is noise. A short file that says "here's who we are and here are the key pages, in plain text" can make it easier for an AI tool to understand you, especially when it's fetching pages at the moment someone asks a question.

The honest status

It's a proposal, not an established standard enforced by search engines. Adoption by the major AI providers is uneven and changes over time, and providers have generally not committed to using it for ranking or citations. So treat it as a low-cost, low-risk addition, not a guaranteed visibility boost. Check current documentation from the tools you care about.

Reasons to add one anyway:

• It takes under an hour.
• It forces you to write a clear summary of your product.
• Some developer tools and AI agents do read it.
• It's harmless if ignored.

What goes in it

The proposed format is Markdown with a specific structure:

• An H1 with the site or project name (required).
• A short blockquote summary.
• Optional paragraphs of context.
• Sections (H2) containing lists of links, each with a brief description.
• An optional "Optional" section for less important links.

Example

# Acme Scheduler

> Acme Scheduler is scheduling software for small clinics. It handles bookings, reminders and payments.

Key facts: for clinics with 1 to 20 staff; pricing starts at $29/month; integrates with Google Calendar and Stripe.

## Product
- [Features](https://acme.example/features): what it does
- [Pricing](https://acme.example/pricing): plans and limits
- [Integrations](https://acme.example/integrations): supported tools

## Help
- [Getting started](https://acme.example/docs/start): setup in ten minutes
- [FAQ](https://acme.example/faq): common questions

## Optional
- [Blog](https://acme.example/blog): guides for clinic owners

Writing a good one

• Lead with plain facts. Who it's for, what it does, price range, limits.
• Describe links usefully. A few words on what each page contains.
• Keep it short. Link only to your most important pages.
• Keep it accurate. Update it when pricing or features change.
• Don't hide instructions in it. Attempts to manipulate models are bad practice and may be penalised.

Related files

• robots.txt controls which crawlers may access what. Make sure you're not blocking crawlers you want.
• sitemap.xml lists URLs for search engines.
• llms-full.txt is a variant some sites publish with the full text of key documentation.

Do you need one?

• Documentation-heavy or developer products: likely worth it.
• Content sites and SaaS: optional; a good use of an hour.
• Small local business: low priority. Fix your Google Business Profile and site clarity first.

The bigger levers for AI visibility are described in getting recommended by ChatGPT and SEO for startups.