llms.txt Complete Guide — Format, Examples, and FAQ

llms.txt is an emerging standard sometimes called "robots.txt for LLMs". This guide covers the format, where to place it, the difference between llms.txt and llms-full.txt, and common implementation pitfalls.

What is llms.txt?

llms.txt is a proposed standard from llmstxt.org — a Markdown file served at /llms.txt that describes your site and links to its key pages for LLMs to efficiently understand.

LLMs can read raw HTML, but ads, navigation, and footers add noise that wastes tokens. llms.txt lets a site proactively say "here's what matters" in a compact form, improving both token efficiency and summary accuracy.

Basic format

llms.txt is plain Markdown. The minimum useful content is:

# H1 — site name
> blockquote — 1-2 sentence summary
## Sections + link lists — key pages with short descriptions

Concrete example

# DevForge

> Project management tool for solo developers. Projects, TODOs, analytics, site audits, and portfolio publishing — all free, all in one place.

DevForge is built for solo developers who ship multiple side projects. It integrates Google Analytics and Search Console, audits sites for security/SEO/LLMO, and publishes projects as a portfolio.

## Core features

- [Project management](https://devforge.itlibra.com/en): Centralize status, stack, TODOs, URLs
- [LLMO Checker](https://devforge.itlibra.com/en/llmo): Audit llms.txt, JSON-LD, AI crawler access
- [Site Audit](https://devforge.itlibra.com/en/site-audit): 26-item security/SEO/LLMO/integration audit
- [Multi-site Analytics](https://devforge.itlibra.com/en/multi-site-analytics): GA4 + Search Console in one view

## Resources

- [Home](https://devforge.itlibra.com/)
- [Sign up](https://devforge.itlibra.com/en/register)
- [Privacy](https://devforge.itlibra.com/en/privacy)

llms.txt vs llms-full.txt

llms.txt is a concise overview + links. llms-full.txt is a Markdown version of the full site content. For documentation-heavy sites or product pages where you want the full content available to LLMs, publish both.

Which should I create first?

Start with llms.txt — it's small (a few KB) and always useful. Add llms-full.txt later if you want specific documentation pages trained on by LLMs.

Location and Content-Type

Place /llms.txt and /llms-full.txt at the site root. Recommended MIME type is text/markdown or text/plain. For Next.js, just drop a static file in public/llms.txt.

FAQ

Q. Does llms.txt help with regular SEO?

Not directly — it's an LLM-targeted standard, not a Google ranking factor. But it may indirectly drive traffic via AI Overviews citations.

Q. How is it different from robots.txt?

robots.txt controls crawler access (allow/disallow). llms.txt describes content for LLMs. Completely different roles — publish both.

Q. Does it work if my site is a JavaScript SPA?

Yes, llms.txt itself is static. But if the pages it links to are SPAs with empty HTML, LLMs still can't read those pages. Consider SSR/SSG for the linked pages.

Q. Does publishing llms.txt mean my content will be used for training?

That depends on the AI crawler's policy. llms.txt is a "hey here's what matters" hint, not a training opt-in. Training opt-out is controlled via robots.txt.

Verify your setup

After publishing llms.txt, run your site through DevForge's LLMO Checker to confirm it's properly detected.