llms.txt — What is behind it and why is it important?

With the rapid development of AI technologies, large language models (LLMs) such as ChatGPT, Google Gemini or Bing Chat are fundamentally changing how users access information on the web. These AI-powered systems crawl websites to provide users with quick and contextual answers. However, they face challenges: Comprehensive HTML code, complex navigation, scripts and even classic SEO mechanisms (such as locking via robots.txt) make it difficult for AI models to efficiently recognize the relevant content of a website. This is exactly where the llms.txt file has recently come into play, which is considered a new hot topic in SEO circles.

In this article, we'll explain what the llms.txt file is all about, how it works and how it differs from a robots.txt. We show why this topic is so dynamic — there are no final standards yet — and why it is all the more important in the age of LLMs to stay on track with SEO and “GEO” (Generative Engine Optimization).

What is llms.txt?

The llms.txt is a simple text or markdown file that is located in the root directory of your website (similar to robots.txt). Its purpose is to give AI language models a structured overview of the most important content on your website.

You can think of llms.txt as a kind of site map for AI assistants — but not to list all pages for crawlers, but to help AI systems semantically understand and correctly summarize the content.

Unlike a normal site map (which primarily serves search engine crawlers), llms.txt contains a curated summary of your offer in plain language. The file describes what your site is about and what key information is available so that an AI model can quickly capture it when needed. For example, a llms.txt from an online shop website could contain the main product categories, important service pages (shipping, return policy), and brief descriptions of the shop's unique selling points. The aim is for an AI model — such as a chatbot with web access — to understand the structure and content at a glance, instead of having to laboriously parse the entire website. Since LLMs only have limited context windows and can't process an infinite amount of content at the same time, the compressed llms.txt provides an efficient way to deliver the essence of your site to AI.

Important: The idea of llms.txt is still new and is constantly evolving. It is a proposed standard (since the end of 2024) that is currently being tested by the community. There is no guarantee that every AI will actually read or use your llms.txt — rather, it is intended as a signal to make work easier for future AI systems. For example, Google has not yet announced official support for llms.txt. However, some platforms and CMS already allow you to upload a llms.txt, and initial tools and discussions show that this approach is becoming more important.

Difference from robots.txt

At first glance, llms.txt is reminiscent of the classic robots.txt in terms of location and file format — but the purpose and content differ significantly. Here are the main differences:

• Objective: A robots.txt regulates which areas of a website may be visited or indexed by search engine crawlers (classic SEO goal). The llms.txt, on the other hand, is aimed at AI systems and is intended to support Generative Engine Optimization (GEO) — i.e. the optimal presentation of your content in AI-generated answers.
  → In short: robots.txt = crawl control for search engines, llms.txt = content preparation for AI.
  
• Target group: Robots.txt addresses search engine bots (Googlebot, Bingbot, etc.), while llms.txt is specifically intended for AI models and chatbots. For example, llms.txt should help ChatGPT, Bing Chat, Claude, or future AI assistants understand your website better.
• Content & format: The syntax of a robots.txt is very simple (allow/disallow rules in text form). A llms.txt file, on the other hand, uses a Markdown structure that is easy to read by both humans and machines. It does not contain instructions for crawling, but rather an overview of key content: headings, short descriptions, and lists of links to important pages or documentation. This structure makes it easier for LLMs to process the information (Markdown is easier for them to interpret than complex HTML).
• Relationship with SEO: Robots.txt has always been a part of search engine optimization (SEO) to guide crawlers. The llms.txt is in the context of AI optimization (GEO). You could say that llms.txt adds the dimension of AI comprehensibility to SEO. While good SEO ensures that your content is found in Google & Co., GEO aims to ensure that your content is also understood and correctly displayed by AI systems. Both approaches can complement each other: A llms.txt does not conflict with robots.txt, but can instead usefully complement it by providing additional context for permitted content.

How do you create a llms.txt? — Content and best practices

Since llms.txt is not yet a binding standard, there are different approaches. However, some best practices have already emerged:

• Clear structure in Markdown: Use headlines and lists to organize content clearly. Start with a # title (name of your project or company) and include a short description with the most important facts in a block quote. This is followed by further sections (## heading), in which you explain details or list groups of links.
  
• Prioritize important content: Only include essential information and avoid unnecessary ballast. Ask yourself the question: What should an AI model absolutely know about my website in order to answer user queries correctly? These are exactly the points that belong in the file.
• Clear, simple language: Write as if you were explaining your company to a new team member. Marketing jargon or flowery advertising slogans are out of place. Instead of “We offer innovative, cutting-edge solutions,” explain in concrete terms what you offer and for whom. A llms.txt should sound like a well-formulated guide for a helpful assistant.
• Examples and specific information: Where possible, provide examples, data, or brief facts that prove your added value. Link to more detailed pages/documents and add a brief explanation of what can be found there. For example:
  - [API documentation] (https://deinedomain.ch/api-docs): Technical details of our interfaces
• Technical notes: Keep the file small (less than 100 KB) and in UTF-8 text format. Avoid complex embeds, scripts, or HTML code — pure text structure in Markdown is enough. Optionally, you can include a ## Optional section that contains further but not critical information. This can be ignored by AI models if the context size is tight.
  ‍Important: Don't contradict the information in your robots.txt with your llms.txt (e.g. don't list URLs that robots say are blocked).
• Update regularly: Your website is alive — the llms.txt should also always be kept up to date. Plan to revise the file if there are major changes to the content so that AI systems always have fresh and accurate information.

Outlook: SEO and GEO are changing

The introduction of llms.txt underscores a larger trend: The world of search engine optimization is changing due to AI and generative search. Users are increasingly getting answers from chatbots or AI search results instead of clicking through classic link lists. For you as a website operator, this means that, in addition to classic SEO, Discoverability in AI answers To keep an eye on — just Generative Engine Optimization (GEO).

llms.txt is still an experimental concept and not an official ranking factor. Not every AI is already using this file, and there is currently no general guideline from the major search engines. Nevertheless, the first early adopters are jumping on: developer communities discuss best practices, content management systems such as Drupal offer modules to support llms.txt, and industry blogs share experiences. It is quite possible that llms.txt (or a similar format) will become more important in the future — whether because AI bots are specifically looking for it, or because new tools are being created that aggregate these files.

For you, that means staying tuned! Even though no immediate jumps in traffic are expected today, it's worth keeping an eye on developments and adapting your SEO strategy early on. Creating a llms.txt can be a useful step to make your content more AI-friendly and stay ahead of the competition. And even if standards change — the thought process of clearly defining your most important content and preparing it in a structured way won't hurt your overall strategy.

Conclusion: Mastering the future with experts

LLMs and generative AI will continue to change the rules of the game in online marketing. The llms.txt file is a current example of how new tools and standards are being formed to make website content more usable for AI. Much is still in flux and binding standards are missing — it is all the more important to remain flexible and proactively address new trends. Anyone who deals with topics such as llms.txt, GEO and AI optimization at an early stage will have a long-term advantage when it comes to being present in AI-generated answers.

A collaboration with an experienced SEO agency, which keeps an eye on both classic SEO and the latest developments in GEO, is definitely an advantage here. This ensures that your website is ideally positioned not only for Google & Co., but also for the next generation of search — no matter where the LLMs are going to travel.