What Is llms.txt and How to Create One (2026 Guide)

If you have never heard of llms.txt, you are not alone, but the businesses that adopt it early are the ones showing up in ChatGPT, Perplexity and Gemini answers right now. It is a small text file with a big job: telling AI models exactly what your website is about, in a format they can actually use.

Google has spent two decades teaching websites how to talk to search crawlers. AI models work differently, and llms.txt is the first real attempt at a shared standard for that conversation. Here is what it is, why it is worth your time, and how to set one up properly.

What Is llms.txt?

llms.txt is a plain text file, placed at the root of your domain (yourdomain.co.uk/llms.txt), written in simple Markdown. It gives large language models a clean, structured summary of your site: who you are, what you offer, and which pages matter most.

Think of it as a curated briefing document for AI. Instead of asking a model to crawl and interpret dozens of pages, guess at your navigation, and wade through cookie banners and JavaScript, llms.txt hands it the short version straight away.

The format was proposed in 2024 by developer Jeremy Howard, and it has picked up steady adoption since, particularly among SaaS companies, documentation sites and content-heavy businesses that want to control how AI systems represent them.

Why llms.txt Matters for AI Visibility

Search behaviour is shifting. A growing share of UK consumers now start their research in ChatGPT or Gemini rather than Google, especially for comparison and “best of” style questions. That shift has created a new discipline, generative engine optimisation (GEO), sitting alongside traditional SEO. If you want the fuller picture of how the two disciplines differ, see our guide on SEO vs GEO.

llms.txt is one of the few direct levers you have in that discipline. A few reasons it matters:

• AI models cannot always parse complex websites well. Heavy JavaScript, pop-ups and inconsistent structure can confuse a crawler that Google’s more mature bots would handle without issue. llms.txt sidesteps that entirely.
• You control the summary. Rather than hoping an AI model correctly infers what your business does from scattered pages, you state it directly.
• It supports citation. When an AI answer references a source, a well-structured llms.txt increases the odds your site is the one it pulls from and links to.
• Early adoption is still a differentiator. Most UK small and medium businesses have not implemented llms.txt yet, which means the ones who do stand out to AI crawlers that are actively looking for well-structured sources.

None of this replaces solid SEO fundamentals. It sits alongside them.

llms.txt vs robots.txt vs sitemap.xml

These three files often get mixed up, so it is worth being precise:

• robots.txt tells crawlers what they are allowed or not allowed to access. It is a permissions file.
• sitemap.xml lists every URL on your site so search engines can find them. It is a discovery file.
• llms.txt explains what your site is and what matters most, in language a model can use directly. It is a context file.

You need all three, and they serve different purposes. llms.txt does not replace your sitemap or your robots directives, it adds a layer of interpretation on top.

What Should You Include in an llms.txt File?

The emerging convention follows a simple Markdown structure:

# Company Name

> One or two sentence summary of what the business does and who it serves.

## Key Pages
- [Services](/services): Short description of this page
- [Pricing](/pricing): Short description of this page
- [Case Studies](/case-studies): Short description of this page

## About
Additional context: founding story, specialisms, geographic focus, or anything that helps a model represent the business accurately.

## Contact
- Website: yourdomain.co.uk (not a real link, just an example)
- Email: hello@yourdomain.co.uk

Keep each page description factual and specific. Avoid marketing fluff, since the goal is clarity for a machine, not persuasion for a human reader.

How to Create an llms.txt File: Step by Step

1. Audit your site. List the pages that best represent your business: core services, pricing, key guides, case studies, and your about page. Leave out thin or duplicate content.
2. Write a clear one-line summary. State what the business does and who it is for, in plain English, with no jargon.
3. Structure it in Markdown. Use the format above: an H1 with your company name, a short blockquote summary, then organised sections with links and descriptions.
4. Keep descriptions short and accurate. One sentence per link is usually enough. Match the description to what is actually on the page.
5. Save the file as llms.txt and upload it to the root of your domain, so it is reachable at yourdomain.co.uk/llms.txt.
6. Test accessibility. Open the URL directly in a browser to confirm it loads as plain text, not a 404 or a redirect.
7. Review quarterly. Update it whenever you add major new pages, change positioning, or launch new services.

Most website builders and CMS platforms allow you to upload a static file to the root directory. If you are on WordPress, this typically means using an FTP client or a plugin that permits root-level file uploads, since the standard media uploader will not place it correctly.

Best Practices for llms.txt in 2026

• Be concise. Long files dilute the signal. Prioritise your 10 to 15 most important pages rather than listing everything.
• Keep it current. An outdated llms.txt pointing to old pages or dead links is worse than having none at all.
• Match your on-page content. llms.txt is a summary, not a substitute. The pages it links to still need strong, well-structured content to back up the claims.
• Pair it with structured data. Schema markup and llms.txt work well together, since both aim to make your content machine-readable, just for different systems.
• Do not treat it as a ranking hack. There is no confirmed evidence it directly influences AI citation frequency on its own. It is one input among many, alongside E-E-A-T signals, content quality and backlinks.

Common Mistakes to Avoid

• Writing llms.txt in dense paragraphs instead of clean Markdown structure
• Linking to pages that no longer exist or have been redirected
• Copying generic marketing copy instead of factual, specific descriptions
• Forgetting to update it after a site redesign or rebrand
• Treating it as a replacement for good site architecture, rather than a complement to it

FAQ

Does llms.txt guarantee my site will be cited by ChatGPT or Gemini? No. It improves how clearly AI models can interpret your site, which supports the chances of citation, but it does not guarantee it. Citation still depends heavily on content quality, authority and relevance to the query.

Is llms.txt an official web standard? Not yet in the way robots.txt is. It is a proposed convention that a growing number of AI-focused companies and websites have adopted, and it is increasingly recognised by AI crawlers, but there is no formal governing body enforcing it.

Where exactly should the file live? At the root of your domain, so it is accessible at yourdomain.co.uk/llms.txt, the same way robots.txt sits at yourdomain.co.uk/robots.txt.

Do I need a developer to create one? Not necessarily. Writing the file itself only requires basic Markdown. Uploading it to your domain’s root may need developer or hosting access, depending on your platform.

Should every business create one? Any business that wants to be well represented in AI-generated answers benefits from it, but it matters most for businesses whose customers research online before buying, such as B2B services, SaaS and professional services.

Final Thoughts

llms.txt will not transform your AI visibility on its own, but it removes friction between your website and the models increasingly used to research, compare and recommend businesses. It takes under an hour to set up properly and costs nothing beyond that time.

If you want your site properly structured for both traditional search and AI answer engines, that is exactly the kind of groundwork an AI-focused SEO strategy should cover from day one. If you are working from the ground up, our complete guide to SEO for small business covers the fundamentals this sits on top of. For a tailored plan, see our SEO pricing for UK businesses.