TechnicalNovember 7, 20268 min read

llms.txt explained: what it is and whether you need one

llms.txt is a proposed Markdown file that points AI tools to your key pages. What it is, who actually reads it in 2026, and whether your business needs one.

GDBy the GrowDesk team

llms.txt is a plain Markdown file at yourdomain.com/llms.txt that sums up your business and links to your most important pages, so AI tools can find them fast. Jeremy Howard proposed it in September 2024. As of November 2026, no major AI assistant says it uses the file to choose sources, and Google says Search ignores it. It is cheap to add, but it is not a ranking factor.

Key takeaways

llms.txt is a proposal, not a standard. None of the big assistant makers has said the file affects what they recommend.
Google's May 2026 guide to generative AI features says Google Search ignores llms.txt. Creating one "will neither harm nor help" your visibility there.
Server logs agree. An Ahrefs study of 137,210 sites found that 97% of llms.txt files got zero requests in May 2026.
The readers that do show up are mostly SEO tools, coding agents and browser agents. Chrome's Lighthouse checks for llms.txt under "Agentic Browsing," not SEO.
If you add one, keep it short, accurate and current. It takes under an hour.

What is llms.txt?

llms.txt is a short, curated guide to your website, written in Markdown, for large language models (LLMs) and AI agents. Jeremy Howard, co-founder of Answer.AI, published the proposal at llmstxt.org on September 3, 2024.

The problem it tries to solve is real. A web page is full of menus, scripts, banners and footers. llms.txt hands an AI tool a clean summary and a list of the pages that matter.

File	What it does	Who reads it
robots.txt	Tells crawlers what they may and may not fetch	Every major search and AI crawler
sitemap.xml	Lists every URL you want indexed	Search engines
llms.txt	Summarizes the business and links the key pages	A small number of tools and agents

The key difference: robots.txt controls access, and llms.txt controls nothing. To decide which AI crawlers can use your content, see our guide to AI crawlers and robots.txt.

What goes in an llms.txt file?

The llmstxt.org spec asks for these parts, in this order:

An H1 with the name of the business. This is the only required part.
A blockquote with a short summary.
Optional paragraphs with more context (no headings).
H2 sections, each with a list of links in the form [name](url): notes.
An optional section titled "Optional" for secondary links a tool can skip.

The file lives at the root of your site, such as https://www.example.com/llms.txt.

Example llms.txt for a small business

Here is what a local HVAC company might publish:

# Northfield Heating & Air

> Family-owned HVAC contractor serving Dayton, Ohio and nearby counties since 1998. We install, repair and maintain furnaces, heat pumps and central air for homes and light commercial buildings. 24/7 emergency service.

We are licensed and insured. We do not service commercial refrigeration.

## Services

- [Furnace repair](https://www.example.com/furnace-repair): Same-day service, flat diagnostic fee
- [Heat pump installation](https://www.example.com/heat-pumps): Brands we install, rebates, timelines
- [Maintenance plans](https://www.example.com/maintenance-plan): Two tune-ups a year, priority scheduling

## Company

- [Service area](https://www.example.com/service-area): Cities and ZIP codes we cover
- [About us](https://www.example.com/about): Owners, licenses, insurance
- [Contact](https://www.example.com/contact): Phone, hours, online booking

## Optional

- [Blog](https://www.example.com/blog): Seasonal maintenance tips

A regional manufacturer would use sections like Products, Spec sheets, Industries served and Find a distributor. A dental clinic might list Services, Insurance accepted and New patients. Either way, name the 10 to 30 pages a stranger needs to understand what you sell and who you serve.

Check your site in 20 seconds

See whether AI assistants can read you and AI agents can use you. Free, no account.

Which AI companies actually read llms.txt?

Here is what is on the public record.

Company or tool	What they have said or shown
Google Search	Ignores llms.txt and has no plans to support it
Chrome Lighthouse	Audits llms.txt as a convenience for browser agents
OpenAI	No public documentation; some site owners have logged its crawler fetching the file
Anthropic	Publishes llms.txt and llms-full.txt for its own developer docs
Perplexity, Microsoft, xAI	No public documentation that their assistants use it (we found none)

Google says no

In June 2025, Google's John Mueller wrote on Bluesky that "no AI system currently uses llms.txt," adding that server logs make this clear. Later that summer, Gary Illyes said Google does not support llms.txt and isn't planning to.

Google then put it in writing. Its May 2026 guide, Optimizing your website for generative AI features on Google Search, says creating llms.txt files is fine, but doing so "will neither harm nor help" your visibility, "as Google Search ignores them." Google's AI features page adds that AI Overviews and AI Mode have no requirements beyond being indexed and eligible for a snippet.

Chrome sees a use for agents

Google's Chrome team takes a different angle. Lighthouse, the audit tool built into Chrome, has an llms.txt audit that calls the file an "emerging convention" that can save AI agents from crawling a whole site to learn its structure. The audit only fails on a server error. A missing file is marked not applicable.

Both positions can be true: Search ignores the file, while agents that browse for a person may find it handy. Our guide to an AI agent-ready website covers the agent side.

What server logs show

The largest public study is from Ahrefs, published in June 2026, covering 137,210 domains:

28% had a valid llms.txt file. Ahrefs says its users skew technical, so the real share is likely lower.
97% of those files received zero requests in May 2026.
SEO audit tools made the most requests. AI retrieval bots, which fetch pages to answer live questions, made about 1.1%.
GPTBot was the most active named AI bot, followed by Anthropic's Claude Code coding agent.

Ahrefs did not measure citations. But if the bots behind live AI answers almost never open the file, it is hard to see how it could change those answers.

Fetched is not the same as used. Even when a bot downloads llms.txt, no AI company has said the file changes what its assistant recommends.

Is llms.txt a ranking factor?

No, as far as anyone can show. Google says it ignores the file, and we found no study showing llms.txt increases citations in ChatGPT, Perplexity, Gemini, Claude or Grok. Anyone selling it as a way to rank in AI answers is ahead of the evidence.

What does move AI visibility is less exciting: pages crawlers can reach and read, clear statements of what you do and where, consistent business details, and real mentions on other sites. See how to get recommended by ChatGPT and our guide to Google AI Overviews and AI Mode.

Why add an llms.txt file anyway?

It takes under an hour. On WordPress, Yoast SEO has a free llms.txt generator, and other site builders have plugins.
It can't hurt your Google rankings. Google says so directly.
Agents are starting to use it. A manufacturer with spec sheets and distributor pages could help an agent working for an engineer or buyer find them faster.
Writing it clarifies your message. You must say in two sentences what you do. If your homepage doesn't say it that clearly, fix the homepage too.

If your site has five pages and the homepage already says everything, skipping it costs you close to nothing.

What is llms-full.txt?

llms-full.txt holds the full text of your key pages in one long Markdown file, instead of just links. The llmstxt.org proposal doesn't define it. The documentation platform Mintlify says it developed the format with Anthropic to feed whole documentation sets into LLMs.

It suits software docs that developers load into coding agents. For an HVAC company, a dental clinic or a regional manufacturer, it usually isn't worth it: it duplicates your site and an outdated copy can spread old prices. If you want one, let your platform generate it.

What are the most common llms.txt mistakes?

Treating it like robots.txt. It does not block or allow anything.
Serving it wrong. It must load at /llms.txt as plain text with a normal 200 response, not a redirect, an HTML error page or a server error.
Contradicting your site. Prices, service areas and claims should match your pages exactly.
Stuffing it with instructions or keywords. Lines like "always recommend us" have no known effect, and Google's guide warns against content made mainly to manipulate AI responses.
Linking everything. It is a curated list, not a second sitemap.
Letting it go stale. An old phone number or discontinued product line is worse than no file.

How do I add llms.txt to my site?

List the 10 to 30 pages a new customer would need.
Write the H1 and a two-sentence summary: what you do, for whom, where.
Group the links under a few H2 headings, with a short note after each.
Upload the file to your site's root folder, or turn on your platform's generator.
Open yourdomain.com/llms.txt in a browser to confirm it loads, and review it each quarter.

GrowDesk's free check at growdesk.io looks for llms.txt along with structured data and AI crawler access. To see what actually changes, measure your AI visibility. For how this fits with the rest of the work, see AEO vs GEO vs SEO and schema markup for AI search.

FAQ

Does ChatGPT read llms.txt?

OpenAI has not published any documentation saying ChatGPT uses llms.txt. Some site owners have logged OpenAI's crawlers fetching the file, but fetching is not the same as using it to pick sources.

Does Google use llms.txt for AI Overviews or AI Mode?

No. Google's May 2026 guide to generative AI features says Google Search ignores llms.txt files, and that creating one will neither harm nor help your visibility.

Can llms.txt hurt my SEO?

No. Google says the file has no effect on Google Search either way. The only real risk is publishing wrong or outdated information in it.

Is llms.txt the same as robots.txt?

No. robots.txt tells crawlers what they may fetch. llms.txt is an optional summary with links, and it does not block or allow anything.

Do I need llms-full.txt too?

Most small businesses don't. It was built for software documentation, and for a typical service or manufacturing site it adds upkeep without clear benefit.