Heard of llms.txt? No? You’re not alone, and you’re definitely not behind.
Let’s be honest. This isn’t something most clients are hearing about on a webinar or seeing in their analytics dashboards. It’s a niche proposal for now, but an interesting one.
As AI tools like ChatGPT, Copilot and Gemini keep changing how people search, read and research, website content is being pulled into answers, summaries and snippets in ways that aren't always accurate or fair. These answers are often generated using AI crawlers trained on content from websites that may not be structured in a way that works best for AI systems. And that’s where llms.txt comes in.
It’s a small, simple way to say, "Here’s what we want you to do with our content", and it could be an early step towards having more control over how AI models treat your site. It's one of the first signs of AI content control becoming a more mainstream consideration.
So, what is it, and do you need one?
Let’s take a look.
What is an llms.txt file?
It’s a plain markdown file (or simple .txt file) that lives at the root of your website, like yourdomain.com/llms.txt.
In it, you can include short, human-readable statements that give AI models a bit more guidance about your site. Things like:
- What your website is about
- Which parts of your site are the most accurate or authoritative
- How you’d prefer your content to be cited, referenced or summarised
- Whether you allow your content to be used for AI training purposes
The idea comes from llmstxt.org, a community-led initiative trying to create a consistent way for website owners to interact with large language models (LLMs). These are the systems powering the big-name chat model tools that are now sitting in people’s browsers, search bars and smartphones.
Think of it a bit like robots.txt for AI, but for AI, not search engines.
Why it matters
We’ve hit a new phase of the internet. AI tools are now answering questions that people used to type into Google, and they’re doing it using live web content, often without proper attribution or context.
That means your content might be quoted, paraphrased or referenced without you even knowing. And that can cause problems, especially if you’re sharing time-sensitive, regulated or reputation-critical information.
Here’s why llms.txt is worth considering.
1. It could reduce misrepresentation
If AI models are going to summarise your content, you want them looking at the right pages. This file lets you point to the content that reflects your current thinking or your most trusted advice, a useful tool for improving AI-digestible content and delivering detailed information to AI systems more effectively.
2. AI models read differently to Google
Traditional SEO crawlers focus on things like metadata, headings and sitemaps. AI models care more about documentation structure, language patterns, and context window. They don't index pages, they interpret them.
llms.txt is a way to add a bit more structured content to that process, helping AI interpret your HTML pages, site title, and core messaging with greater clarity.
By doing this, you increase the chances of your content being understood as LLM-friendly content, aligning better with how AI engines process user queries.
3. You can set expectations
You can use the file to say whether you're happy for your content to be used in AI training. It won't stop everyone from doing it, but it does show intent, and that could matter legally, ethically or commercially in future.
It also supports organisations managing developer docs, API documentation, or other documentation files that they may not want used out of context.
For brands that expose API methods, product data, or URLs per Post Type, it can help reinforce what should and shouldn't be surfaced via Retrieval-Augmented Generation tools like ChatGPT Browse.
4. It's a low-lift way to show digital leadership
This won’t affect your rankings or traffic today, but for organisations that want to stay ahead of the curve, especially those with a strong brand voice or unique content, it’s a small but meaningful move.
Adding this kind of control to your Content Management practices could become part of a more future-ready AI SEO toolkit. It also gives your team more say in the site's content structure, paving the way for smarter automation and more ethical use of your digital assets.
Will Umbraco support this?
It might, eventually. If adoption grows, it would make sense for CMS platforms to add support, either through core functionality or packages. But that’s not something we’d expect to see straight away.
The good news is, you don’t need to wait. This is something Gecko can implement for you now, either manually, or in a way that makes future updates simple for your team. We can also ensure that your index file, post types, or exclude posts preferences are carried through into the setup, and even accommodate any Exclude Terms or taxonomy preferences you want in the future.
So, should you add one?
If you’re in a content-heavy, trust-based or regulated sector - education, health, professional services, government, non-profit - then it’s worth considering. Especially if you’ve already had conversations internally about content ownership or AI usage.
If you’re not in that space, and don’t have the capacity to maintain another bit of digital housekeeping, it’s perfectly fine to wait. There’s no penalty for doing nothing. But there might be an opportunity to show leadership by doing something small, early.
And that’s the key point, right now, this is about being proactive, not reactive.
What would it involve?
We’d work with you to:
- Review the content on your site and decide what to highlight
- Draft a clear, readable llms.txt file that aligns with your goals
- Add it to your root domain and make sure it stays up-to-date over time
It’s not a big project, but it’s the kind of thing we love. Clear, purposeful, quietly strategic.
For now
If you’re curious, the full spec is at llmstxt.org. But if you just want to chat about whether it makes sense for your organisation, from internal linking to custom file setup, drop us a line.
Whether you’re managing a large language models website, running editorial content, or offering high-value documentation, we’ll keep tracking how this develops, and if it becomes a widely adopted standard, we’ll be ready to help you roll it out at scale.
Want to explore what it could look like for your website? Give us a shout.
