---
title: "llms.txt Explained: What It Is and Do You Need One?"
description: "What llms.txt is, how it differs from robots.txt and sitemaps, whether it helps AI visibility, and a ready-to-adapt example with llms-full.txt."
canonical: "https://ossvy.com/blog/llms-txt"
lang: "en"
dir: "ltr"
dateModified: "2026-10-09"
type: "blog-post"
author: "Selin Arıkan"
reviewedBy: "Karim Nassar"
datePublished: "2026-10-09"
category: "Guides"
source: "Ossvy (https://ossvy.com)"
---

# llms.txt explained: do you need one?

A plain Markdown file that tells language models what your site is and where the important pages are. What it does, what it doesn't, and how to write one in 15 minutes.

> In short: llms.txt is a Markdown file at your site's root that summarizes the site for language models and links to its key pages. It was proposed in 2024 and isn't an official standard. No major AI search engine has confirmed using it to choose sources, so treat it as a cheap extra, not a strategy.

- llms.txt is a proposal, not a standard, and not a ranking factor.
- It helps tools and agents that fetch it on purpose, such as coding assistants.
- It costs little to add, but crawlable pages matter far more.

Breadcrumb: [Home](https://ossvy.com/index.md) › [Blog](https://ossvy.com/blog.md) › [Guides](https://ossvy.com/blog/category/guides.md) › llms.txt explained: do you need one?

## What is llms.txt?

llms.txt is a plain-text Markdown file, served at `/llms.txt`, that tells language models what your website is about and links to the pages that matter most. It was proposed in September 2024 by Jeremy Howard of Answer.AI ([llmstxt.org](https://llmstxt.org/)).

The idea is simple. Web pages are full of navigation, scripts, cookie banners and layout that a model has to strip away to find the content. A short, structured Markdown file gives a model a clean summary and a map in one request. The proposal also suggests offering clean Markdown versions of key pages, at the same URL with `.md` added.

It's worth being precise about the status: llms.txt is a community proposal. It isn't an IETF or W3C standard, and no search engine has made it a requirement.

## How is llms.txt different from robots.txt?

Each file does a different job. robots.txt tells crawlers what they may and may not fetch ([RFC 9309](https://www.rfc-editor.org/rfc/rfc9309.html)). A sitemap lists every URL you want indexed. llms.txt describes the site in words and points to a curated set of the most useful pages.

| File | Job | Who reads it |
| --- | --- | --- |
| `robots.txt` | Allow or block crawling | Search and AI crawlers |
| `sitemap.xml` | List all indexable URLs | Search engines |
| `llms.txt` | Summarize the site and link key pages | Tools and agents that choose to fetch it |

llms.txt doesn't block or allow anything. If you want to control AI crawlers, robots.txt is still the file that does it; our [AI crawler list](https://ossvy.com/blog/ai-crawlers-list.md) covers every user agent.

## Does llms.txt improve AI visibility?

There is no public evidence that it does for AI search answers. No major AI search engine has publicly confirmed that it uses llms.txt to choose which sources to cite.

Google is explicit for its own products: you don't need to create new machine-readable files or AI text files to appear in AI Overviews or AI Mode ([Google Search Central](https://developers.google.com/search/docs/appearance/ai-features)). ChatGPT, Perplexity, Gemini and Claude choose sources from what their crawlers and search indexes find on your regular pages.

So if your pages are blocked, slow to render or vague, an llms.txt file won't fix that. Our guide to [how Google AI Overviews choose sources](https://ossvy.com/blog/google-ai-overviews-sources.md) explains what does count there.

## Where does llms.txt actually help?

It helps when a tool fetches it on purpose. The clearest case is developer documentation: coding assistants and AI agents can load a project's llms.txt, or the fuller llms-full.txt, to get the docs in one clean file instead of crawling dozens of pages.

Other useful cases:

- **AI agents** that browse on a user's behalf and look for a quick summary of a site.
- **Internal tools** that feed your public content into a model, such as a support bot.
- **Anyone pasting your site into a chat**, who gets better results from a clean Markdown file than from raw HTML.

For a typical marketing site, the benefit is small but real, and the cost is close to zero. That's why we publish one at ossvy.com.

## What goes in an llms.txt file?

The proposal defines a simple order: an H1 with the site or project name, a blockquote with a short summary, optional paragraphs of detail, then H2 sections that list links with a one-line description each ([llmstxt.org](https://llmstxt.org/)). A section named "Optional" holds links a model can skip when it's short on context.

Here is an example for a fictional invoicing app:

```
# Ledgerly

> Ledgerly is invoicing software for agencies and freelancers in the EU. It sends invoices in 34 currencies and syncs with major accounting tools.

Plans start at €12 per user per month. Data is hosted in the EU.

## Product
- [Features](https://ledgerly.example/features.md): invoicing, reminders, multi-currency
- [Pricing](https://ledgerly.example/pricing.md): plans, limits and billing terms
- [Integrations](https://ledgerly.example/integrations.md): accounting and payment tools

## Docs
- [Getting started](https://ledgerly.example/docs/start.md): setup in 10 minutes
- [API reference](https://ledgerly.example/docs/api.md): endpoints and authentication

## Optional
- [Company](https://ledgerly.example/about.md): team, history and contact
- [Legal](https://ledgerly.example/legal.md): terms, privacy and DPA
```

Keep descriptions factual and short. The file is for models, but the same rule applies as for people: the facts that answer common questions should be easy to find.

## What is llms-full.txt?

llms-full.txt is a companion file that contains the full text of the key pages in one Markdown document, instead of only links. It grew out of documentation sites, where a coding assistant benefits from loading everything at once.

It's optional. For a marketing site, the linked `.md` versions of pages are usually enough. If you publish llms-full.txt, keep it to a sensible size and generate it from the same source as your pages, so it never drifts out of date.

## Should you publish .md page versions?

It's a sensible companion to llms.txt if your platform makes it easy. The proposal suggests serving a clean Markdown copy of a page at the same URL with `.md` added, so a tool that follows a link from llms.txt gets text without layout.

If you do it, three rules keep it safe:

- **Same content as the HTML page.** Generate the Markdown from the same source, never write it separately.
- **Point back to the HTML version.** A canonical link or header tells search engines which version to index, so the copies don't compete.
- **Keep it public and fast.** No login, no JavaScript, a plain text response.

We do this for every page on ossvy.com, and our llms.txt links to the `.md` versions. Because our pages come from structured content, generating the copies was simple. On a hand-built site, start with llms.txt alone.

## Does anyone actually read it?

Check your server or CDN logs for requests to `/llms.txt` and the `.md` URLs, and look at the user agents. You'll typically see a mix of AI crawlers, developer tools and a few curious people. Don't read much into the numbers: a fetch shows the file was read, not that it changed any answer. Measure answers directly with [prompt tracking](https://ossvy.com/product/prompt-tracking.md).

## How do you add llms.txt quickly?

Write it by hand once, then generate it if your site changes often.

1. List the 10 to 20 pages that answer what buyers and users ask most: product, pricing, use cases, docs, comparisons, company facts.
2. Write a two-sentence summary of what you do, for whom and where.
3. Add the facts you most want stated correctly: pricing model, markets, languages, hosting.
4. Group the links under clear H2s, with one line on each.
5. Put legal pages and less important links under "Optional".
6. Serve it at `/llms.txt` as plain text, publicly, with no login.
7. Check that every link works and every fact matches your live pages.

Then put a reminder in your release checklist. An llms.txt with last year's prices is worse than none.

## Who can skip llms.txt for now?

Small sites with a handful of pages gain little. If your site has a home page, a pricing page and a contact form, a model can read all of it directly, and your time is better spent making those pages clear and specific.

Sites with no developer audience and no AI agents in their market can also wait. The file is most useful where tools actively look for it: software documentation, APIs and developer products. Large content sites, such as publishers and marketplaces, may want it for curation, pointing models to the pages that matter among thousands.

Everyone else can treat it as a 15-minute task for a quiet afternoon. It does no harm when the facts are right, and you won't lose anything by waiting until the basics are done.

## What mistakes should you avoid?

The common ones come from treating llms.txt as a shortcut:

- **Writing different claims than your pages make.** If the file says one price and the pricing page another, you've created a contradiction.
- **Stuffing it with keywords.** It's a summary, not a ranking signal.
- **Blocking AI crawlers in robots.txt while publishing llms.txt.** The crawlers that build AI search indexes don't use llms.txt as a substitute.
- **Forgetting it exists.** Stale facts get repeated.

## Summary

llms.txt is a short Markdown summary of your site with links to key pages. It's a 2024 proposal, not a standard, and no major AI search engine has confirmed using it to pick sources; Google says its AI features don't need it. Add one because it's cheap and helps tools that fetch it, then spend your real effort on crawlable, specific pages. Ossvy's [actionable insights](https://ossvy.com/product/actionable-insights.md) show what's blocking you, and the [free AI visibility check](https://ossvy.com/tools/ai-visibility-check.md) shows where you stand.

## Sources

- [llmstxt.org: The /llms.txt file (the proposal)](https://llmstxt.org/) (2024, official)
- [Answer.AI: /llms.txt, a proposal to provide information to help LLMs use websites](https://www.answer.ai/posts/2024-09-03-llmstxt.html) (2024, official)
- [Google Search Central: AI features and your website](https://developers.google.com/search/docs/appearance/ai-features) (2025, official)
- [IETF RFC 9309: Robots Exclusion Protocol](https://www.rfc-editor.org/rfc/rfc9309.html) (2022, standard)

*Statements about llms.txt support come from the public proposal and vendor documentation, checked on the publishing date. The example file describes a fictional company.*

## Questions and answers

### Does ChatGPT use llms.txt?

OpenAI hasn't publicly confirmed using llms.txt to choose sources for ChatGPT search, which relies on its crawlers and search index. Allow those crawlers first; see our [AI crawler list](https://ossvy.com/blog/ai-crawlers-list.md).

### Does Google use llms.txt for AI Overviews?

No. Google says you don't need AI text files to appear in AI Overviews or AI Mode. Read [how Google AI Overviews choose sources](https://ossvy.com/blog/google-ai-overviews-sources.md).

### Can llms.txt hurt my SEO?

Not if its facts match your pages. A file with outdated or contradicting claims can spread wrong information, so keep it current. Ossvy flags wrong facts in [brand sentiment](https://ossvy.com/product/brand-sentiment.md).

### Is llms.txt the same as robots.txt for AI?

No. robots.txt controls what crawlers may fetch; llms.txt only summarizes your site. Use robots.txt to allow AI search crawlers, as explained in our [AI crawler list](https://ossvy.com/blog/ai-crawlers-list.md).

### Where should llms.txt be placed?

At the root of your domain, at /llms.txt, served publicly as plain text. Check that engines can reach your key pages with the [free AI visibility check](https://ossvy.com/tools/ai-visibility-check.md).

Related: [The AI crawler list: GPTBot, ClaudeBot, PerplexityBot and how to allow them](https://ossvy.com/blog/ai-crawlers-list.md) · [How Google AI Overviews choose sources](https://ossvy.com/blog/google-ai-overviews-sources.md) · [Generative engine optimization (GEO): the complete guide for 2026](https://ossvy.com/blog/generative-engine-optimization.md)

**Find out what AI says about your brand**: Start with a free check, or let us walk you through your results in a 30-minute demo. [Start free](https://app.ossvy.com/signup) · [Book a demo](https://ossvy.com/contact?form=demo)

Source: https://ossvy.com/blog/llms-txt · Last updated: 2026-10-09