llms.txt vs robots.txt: What's the Difference?
They look similar — two plain text files sitting at the root of your domain — but robots.txt and llms.txt answer two completely different questions. One governs access. The other offers curation. Confusing the two leads to files that do not do what you expect.
Access control versus curation
robots.txt is an old and widely honored convention — the Robots Exclusion Protocol dates back to the mid-1990s. It is a set of rules that name a crawler by its user-agent and tell it which URL paths it may or may not request. It is fundamentally about access: keep this bot out of that directory, let this other bot roam freely. It says nothing about what your pages mean or which ones matter most.
llms.txt is a much newer proposal — put forward by Jeremy Howard of Answer.AI in 2024 — and it is about curation. Written in Markdown, it gives a large language model a concise, ordered summary of your site: a title, a short description, and grouped links to the pages you most want understood. It does not grant or deny access to anything. A crawler that is blocked in robots.txt is still blocked no matter what your llms.txt says.
What each file looks like
The syntax makes the difference obvious. A robots.txt file is a list of directives keyed to user-agents:
# robots.txt — access rules User-agent: GPTBot Allow: / User-agent: ClaudeBot Allow: / User-agent: * Disallow: /admin/ Disallow: /cart/ Sitemap: https://example.com/sitemap.xml
An llms.txt file, by contrast, is human-readable prose and links — an editorial map, not a rule set:
# Example Co > Independent bakery and coffee roaster in Santa Rosa. ## Core pages - [Menu](https://example.com/menu): Full food and drink list. - [Locations](https://example.com/locations): Hours and addresses. ## Learn more - [Our story](https://example.com/about): How we started. - [Wholesale](https://example.com/wholesale): For cafes and shops.
Side-by-side comparison
Purpose
robots.txt: Controls which crawlers may request which paths.
llms.txt: Summarizes and links your most important content for LLMs.
Format
robots.txt: Directive syntax (User-agent / Allow / Disallow).
llms.txt: Markdown headings, a blockquote description, and link lists.
Enforcement
robots.txt: Voluntary; reputable crawlers document that they honor it.
llms.txt: Advisory only; no rule to obey and no guarantee of ingestion.
Audience
robots.txt: Crawlers and bots deciding what to fetch.
llms.txt: Language models deciding what your site is about.
Do you need both?
For most sites, yes. Use robots.txt to make deliberate decisions about crawler access — whether you want to allow or disallow AI training bots such as GPTBot, ClaudeBot, or PerplexityBot, and to keep any crawler out of private areas like checkout or admin. Then use llms.txt to help the models you do welcome understand your content quickly. The two are complementary: one sets the boundary, the other lays out a welcome map inside it.
A caution worth repeating: llms.txt is not a security or privacy tool. Anything you would be uncomfortable seeing quoted should not be linked from it, and if you genuinely need to keep content away from a crawler, that is a robots.txt or server-configuration job. Because llms.txt adoption is still emerging, treat both files as low-cost, good-hygiene additions rather than guaranteed levers over how any specific AI system behaves.
Frequently Asked Questions
Does llms.txt replace robots.txt?
No. They solve different problems. robots.txt is an access-control convention that tells crawlers which paths they may request. llms.txt is a curation file that summarizes and links your most useful content for language models. Keeping both is the sensible default as of mid-2026.
Can I block AI crawlers in llms.txt?
Not reliably. llms.txt has no defined directives for allowing or denying access, and no enforcement mechanism. If your goal is to stop a crawler from fetching pages, that belongs in robots.txt (or server-level rules), not llms.txt.
Do AI companies read robots.txt?
Reputable operators such as OpenAI (GPTBot), Anthropic (ClaudeBot), and Perplexity (PerplexityBot) publicly document that their crawlers respect robots.txt. Compliance is voluntary and not guaranteed for every bot on the internet, so treat robots.txt as a request rather than a lock.
Where do both files live?
Both sit at the site root: https://example.com/robots.txt and https://example.com/llms.txt. Neither should be nested in a subdirectory, because tools expect to find them at a predictable location.
Which one helps me get cited in AI answers?
If anything does, it is more likely to be llms.txt, since it points models toward your best pages. But there is no guarantee any given AI system reads or uses your llms.txt, so treat it as one signal among many rather than a switch that turns on citations.
Generate a clean llms.txt for your site
Keep robots.txt for access. Let us build the curation file that helps AI models read your content the way you intend.