How many links should my llms.txt contain?

Most sites should list 5 to 15 links. The file's job is curation — agents read it to know what matters. Listing every URL defeats the purpose; if you need to expose more content, add an llms-full.txt companion file instead of bloating the index.

What is the most common llms.txt mistake?

Relative URLs. Links must be absolute (https://your-domain.com/page), not (/page). The second most common is missing or malformed H1 — the file must start with a single # heading containing your site name, followed by a > blockquote summary.

How often should I update llms.txt?

Whenever your site's most important pages change — new core features, new flagship articles, removed sections. There's no need to update it for routine content additions if the curated list stays accurate. Validate after each update.

Spec guide · AI readiness · Updated 2026

llms.txt Best Practices 2026: The 9 Rules for a File AI Engines Trust

The llms.txt spec is short — one required H1, a few conventions — but the difference between a file agents use and a file they ignore is in the details. These nine rules cover format, curation, and maintenance.

1. Start With the H1 — It's the Only Required Element

The first line of llms.txt must be a single Markdown H1 with your site name. Everything else is optional by the spec — but a file with no H1 fails the very first check an agent (or a validator) runs.

# Example Site

2. Write a One-Line Summary as a Blockquote

Right under the H1, a > blockquote telling agents what the site is and who it's for. This is the context an AI engine uses before reading anything else — make it specific, not marketing-speak.

# Example Site

> A SaaS API documentation site for developers building with Example SDK.

3. Curate, Don't Dump

5 to 15 links. The whole point of llms.txt is that an agent can read it in milliseconds and know what matters. If your site needs more material, publish llms-full.txt and link to it — don't turn the index into a sitemap.

4. Use Absolute URLs — Always

Every link must be a full https://your-domain.com/… URL. Relative paths like /docs/start or protocol-relative //example.com/x break agents that fetch the file directly. The one allowed exception is the relative link to llms-full.txt described in the spec.

5. Group Links With H2 Sections

Use ## headings to group related links — Documentation, Blog, Pricing, Support. Agents use these sections to match the user's question to the right part of your site.

## Documentation

- [Getting Started](https://example.com/docs/getting-started)
- [API Reference](https://example.com/docs/api)

## Blog

- [How We Built X](https://example.com/blog/how-we-built-x)

6. Order Links by Importance

The spec has no ranking mechanism beyond order — so your most valuable pages go first within each section. First impressions matter for agents the same way they do for humans.

7. Keep Link Text Descriptive

Use link text that says what the page is ("Getting Started Guide"), not the URL or generic words ("click here"). Agents quote link text when they cite your site.

8. Maintain It Like Code

Regenerate after major content changes (new flagship pages, removed sections).
Validate after every change — our free validator scores spec compliance and flags broken structure.
Generate from your sitemap with the generator when you add many pages at once.
Serve it as text/plain at the site root with no auth, no redirects.

9. Know What It Is — and Isn't

llms.txt is an AI-visibility signal, not a Google ranking factor. Don't neglect robots.txt, sitemap, and on-page SEO because you have it — run all three together (see how they compare), and you're covered for search crawlers and AI agents.

A Complete Reference Example

# Example Site

> A SaaS API documentation site for developers building with Example SDK.

## Documentation

- [Getting Started](https://example.com/docs/getting-started)
- [Authentication](https://example.com/docs/auth)
- [API Reference](https://example.com/docs/api)

## Blog

- [How We Built X](https://example.com/blog/how-we-built-x)
- [Pricing Philosophy](https://example.com/blog/pricing)

[llms-full.txt](llms-full.txt)

That's a file an agent can act on in under a second. Build yours with the generator, check it with the validator, and keep it honest.