---
title: "llms.txt vs robots.txt: What’s the Difference?"
description: "robots.txt controls whether crawlers may access your content; llms.txt describes and links your content for AI agents. One is access control, the other is a guide."
canonical: https://aiovsseo.com/compare/llms-txt-vs-robots-txt.html
date: 2026-06-07
---
# llms.txt vs robots.txt: what’s the difference?

TL;DR

**robots.txt** is access control: it tells crawlers what they may and may not fetch (and, via Content-Signal, how AI may use it). **llms.txt** is a guide: a Markdown file describing your site and pointing agents to key content. One restricts; the other describes. robots.txt is a long-standing standard; llms.txt is an optional, emerging convention.

| Aspect | robots.txt | llms.txt |
| --- | --- | --- |
| Purpose | Control crawler access | Describe & link content for agents |
| Format | Directives (User-agent, Allow, Disallow) | Markdown |
| Status | Established standard | Emerging, optional |
| Required by Google? | Honored for crawl control | No — not required |
| Location | /robots.txt | /llms.txt |

They are complementary, not alternatives. You can and often should have both.

## robots.txt

The decades-old file that governs crawling. Modern usage adds a [Content-Signal](/glossary/content-signal.html) line to separate search indexing, AI retrieval and AI training permissions. This is your access-control layer.

## llms.txt

A newer, optional Markdown file that hands AI agents a curated map of your most important content. It does not control access; it aids navigation. Google has said you don't need it to appear in generative search, so treat it as polish.

## Bottom line

Use robots.txt to set the rules; optionally add llms.txt to make cooperative agents more effective. See [what is llms.txt](/glossary/llms-txt.html).

## Frequently asked questions

**Do I need both llms.txt and robots.txt?**

robots.txt is the important one — it controls crawling and, via Content-Signal, AI usage. llms.txt is optional polish that helps cooperative agents navigate. Having both is fine; having only robots.txt is sufficient.

**Can llms.txt block AI crawlers?**

No. llms.txt only describes and links content; it has no access-control power. To govern crawlers, use robots.txt with Content-Signal directives.