The problem it solves
A modern website is a poor reading experience for a machine. Navigation, cookie banners, animation, duplicated boilerplate, and client-rendered sections all sit between a language model and the twenty sentences that actually describe your business.
llms.txt is a proposed answer: one markdown file at your root that says, plainly, what this site is, what it covers, and which pages matter.
What it is not
- It is not a permissions mechanism. Access control stays in robots.txt.
- It is not a ranking factor in traditional search.
- It is not a place for keyword stuffing. Bloated files defeat the purpose.
- It is not a substitute for structured data, sitemaps, or good page content.
The format
Plain markdown. A typical structure:
Heading one: the organisation or site name.
A blockquote summary: one to three sentences describing what the entity is and does. This is the most important line in the file, because it is the description most likely to be reused.
Optional context paragraphs: a short expansion for nuance.
Sections of links: grouped by purpose, each link followed by a short description of what that page contains.
An optional section of key facts: location, contact, services, sectors served.
Keep it under a few hundred lines. If it starts resembling a sitemap, you have gone too far.
A working example structure
A services business might publish:
- A summary line stating category, location, and who it serves.
- A section listing service areas, each linking to the relevant page with a one-line description.
- A section of key pages: about, work, contact, insights.
- A facts section: legal name, address, contact email, sectors, notable clients.
- An optional section pointing to a fuller llms-full.txt for detail.
The discipline of writing it is itself valuable. Most businesses discover their own positioning is vague only when forced to state it in three sentences a machine will repeat.
Where to put it
At the site root, served as plain text or markdown with a suitable content type, reachable at yourdomain.com/llms.txt. Many sites also publish llms-full.txt with a longer reference version.
Link it from robots.txt if you like, and keep it in version control so it is updated alongside the site rather than forgotten.
What to include for a local business
- Trading name and any common variations.
- What you do, in one sentence, without jargon.
- Cities or regions served.
- Services, distinctly named.
- Sectors or client types.
- Contact email and physical address.
- Links to the pages that expand each item.
What to leave out
- Marketing superlatives. They are unusable and dilute the factual signal.
- Private information, internal URLs, or anything behind authentication.
- Pricing you are not willing to have quoted back to you.
- Claims you cannot corroborate elsewhere, since inconsistency reduces trust.
Maintenance
Treat it as a living document:
- Update when services, address, or positioning change.
- Review quarterly alongside your about page, so the two never disagree.
- Keep the facts identical to your structured data and business listings. Contradictions between sources are exactly what makes a model hedge or omit you.
Is it worth doing?
The cost is an hour. The downside is zero. The upside is that when a system tries to describe your business, there is a clean, self-authored, factually consistent description available in the easiest possible format.
Given how much time businesses spend on marketing assets nobody reads, publishing one file that machines might read is an unusually cheap bet.
