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The llms.txt file is a simple text file in the root of your website with which you allow (or forbid) generative AI systems such as ChatGPT, Google SGE or Perplexity to crawl your content. It works in a similar way to the classic robots.txt – only specifically for Large Language Models (LLMs). If you want visibility in AI overviews today, you should definitely use llms.txt. In this article, you will find out how to do this – including an example, myth check and checklist.
Why you should act now
Imagine you run a website with strong specialist content. Your content is up-to-date and well-structured – and yet you are not named as a source in ChatGPT or Perplexity. The answer could lie in a small file that many people don’t yet know: llms.txt .
Welcome to the age of Generative Engine Optimization (GEO). If you want AI systems to be able to find and correctly cite your content in the first place, you need more than good SEO. You need targeted approval – which is where llms.txt comes in.
What is the llms.txt file - and why is it so important?
The llms.txt ( ⇒ definition of llms.txt ) is the new counterpart to robots.txt ( ⇒ definition of robots.txt ) – but specifically for AI systems. It gives so-called Large Language Models (LLMs) such as ChatGPT, Claude, Gemini or Perplexity clear instructions on which parts of your website they are allowed to crawl and process.
Why this is important:
- More and more people are searching via AI overviews, chatbots or voice search. Read more about this in our blog article: ⇒ GEO KPIs 2025
- AI systems quote content directly, without a traditional click
- If you are not listed, you do not exist for these systems – loss of visibility is imminent
In short: The llms.txt file is your invitation (or block) for AI systems – so that you can control whether and how you appear in their responses.
How does llms.txt work technically?
The llms.txt is a simple text file that you place in the root directory of your domain – e.g. under:
https://deinedomain.de/llms.txt
Structure of the file:
User-agent: *
Allow: /
This gives all AI bots permission to crawl your entire website.
Further options:
Exclude certain areas:
User-agent: *
Disallow: /intern/
Only allow certain AI bots:
User-agent: OpenAI
Allow: /
User-agent: Google Extended
Disallow: /
You can target these bots:
- OpenAI (for ChatGPT Browse)
- Google-Extended (for SGE)
- Anthropic
- PerplexityBot
- CCBot
Common misunderstandings about the llms.txt file
❌ Is robots.txt not enough?
No – many AI systems do not reliably observe robots.txt because they use new crawling methods.
❌ Release means I’m losing control?
On the contrary: without llms.txt, the AI doesn’t even know what it may or may not do. You gain control.
❌ AI crawls everything automatically anyway?
Not true (anymore): Many systems actively pay attention to llms.txt – and do not cite it if it is not released.
llms.txt example - This is what a working file looks like
Here is a tried and tested example of a complete file:
# Release for all LLMs
User-agent: *
Allow: /
# Optional: Release OpenAI specifically
User-agent: OpenAI
Allow: /
#Exclude Google SGE
User-agent: Google-Extended
Disallow: /
Tip: Pay attention to the encoding (UTF-8 without BOM) and the correct line break (Unix/UTF-8).
Tool for validation:
Set up the llms.txt file step by step
- Open a simple text editor (e.g. VS Code, Notepad++)
- Create your instructions as above
- Save the file as llms.txt
- Upload them to the root directory via FTP or CMS (e.g. via a file manager plugin)
- Call up deinedomain.de/llms.txt in the browser – it must be publicly accessible.
Checklist for llms.txt implementation
- File saved in the root directory?
- Syntax and formatting checked?
- All relevant AI bots taken into account?
- Release strategy documented?
- File updated regularly?
- Monitor visibility in Ki systems?
What does llms.txt really do for you?
The advantages at a glance:
- Visibility in ChatGPT, Google SGE, Perplexity & Co.
- Being quoted instead of being overlooked
- Controlled access to sensitive content
- More range – even in zero-click environments
- Basis for your GEO strategy
Especially in combination with structured data, descriptive subheadings and clear answer formats, llms.txt is a powerful tool for your Generative Engine Optimization .
How does llms.txt fit into your GEO strategy?
If you already create content for AI Overviews (FAQs, HowTos, semantically clear articles), then llms.txt is your technical door opener.
Frequently asked questions about the llms.txt file (FAQ)
robots.txt regulates the access of classic crawlers (e.g. Googlebot), llms.txt is aimed specifically at AI crawlers.
No – but anyone who wants to be visible in AI response systems should use it.
OpenAI (ChatGPT), Perplexity, Anthropic, Google (SGE via Google Extended) u.a.
Yes, with Disallow: you can block certain directories or URLs.
Yes – especially via Speakable markup in combination with GEO-optimized content.
Do you need support with GEO & AI visibility?
Then let’s talk – we’ll show you how to get your content into AI Overviews
Concluding words: Small file, big lever
The llms.txt is perhaps the most inconspicuous, but strategically most important text file on your website in 2025. It enables visibility in a system that is increasingly replacing traditional search engines: generative AI:
Make Google your best friend
Find out in my big SEO guide how you can be found online as a self-employed person – clearly, comprehensibly and without technical stress.
About the author:
My name is Isabel Unger, I am an independent digital strategist with a clear focus: visibility for the self-employed & small businesses. My heart beats for SEO, content, structure – and for explaining complex things in a way that makes them understandable and feasible.
On ixtreme.online I share my knowledge, my experience and a lot of plain language – without any technical gobbledygook.
