llms.txt explained: the file that tells AI what your site is about
3 May 2026 · 3 min read
In late 2024, a simple convention emerged from the AI development community: add a plain text file called llms.txt to the root of your website, written specifically for large language models to read. It is not a technical standard yet. There is no W3C specification. But a growing number of AI tools use it - and adding one to your site takes about 20 minutes.
What is llms.txt?
llms.txt is a plain text or markdown file placed at yourdomain.com/llms.txt. Its purpose is to give AI language models a concise, structured summary of who you are, what your site covers, and what your most important pages are - without requiring them to crawl and parse your entire website.
Think of it as an introduction for AI systems. When an AI model crawls your site to understand your brand before generating an answer, a well-written llms.txt file gives it the most accurate, most useful starting point possible - in your words, not inferred from your page structure.
The convention was proposed by Jeremy Howard (co-founder of fast.ai) in 2024. The specification is at llmstxt.org. Anthropic, the company behind Claude, publicly supports the convention and Claude is among the AI tools that reads these files when available.
How it differs from robots.txt
robots.txt tells crawlers what they can and cannot access - it is about permissions. llms.txt tells AI models what your site is about and where to look - it is about understanding. They serve complementary purposes. Your robots.txt should allow AI bots to access your site; your llms.txt should then guide what they find there.
robots.txt is a technical standard with strict syntax rules. llms.txt is a convention with flexible formatting - typically written in markdown, in plain language that an AI model can read and process directly.
What to include in your llms.txt
A well-structured llms.txt file contains four things: a clear description of your business and what you do, a statement of who your content is intended for, links to your most important pages with brief descriptions of each, and any context that would help an AI model accurately represent your brand.
Here is what a basic llms.txt looks like for a service business:
# Mucho Más Mucho Más is an AI search visibility and content improvement partner. We help marketing teams, founders and growth leaders understand how visible their business is across Google, AI search and buyer research journeys - and then deliver the content and structural improvements needed to fix it. ## Key pages - [Free AI Visibility Audit](https://getmuchomas.com/audit): Check your homepage across 7 AI visibility signals, free. - [AI Search Audit](https://getmuchomas.com/visibility-audit): Full 28-check audit with improvement roadmap. - [Content Improvement](https://getmuchomas.com/content-improvement): Rewriting and optimising existing content for AI citation. - [Insights](https://getmuchomas.com/insights): Guides on AI search visibility, content strategy and getting cited by AI.
Does it actually make a difference?
The honest answer is: it helps at the margin, and the margin matters. llms.txt is not a silver bullet - a site with no schema, poor content structure, and blocked AI crawlers will not be saved by adding a text file. But for sites that have the structural basics in place, llms.txt gives AI models a faster, more accurate way to understand your brand.
The strongest argument for adding it is time investment versus potential reward. Writing a good llms.txt takes under an hour. The file then sits on your server indefinitely, available to every AI crawler that visits. For a relatively small effort, it contributes to a more accurate representation of your brand in AI-generated answers.
As more AI tools formally adopt the convention, the benefit will grow. Adding it now is a small investment that compounds over time - and it signals to AI tools that your site is designed for the current web, not the one from five years ago.
What is llms.txt and what does it do?
llms.txt is a plain text file placed at the root of your website (yourdomain.com/llms.txt) that gives AI language models a structured summary of your business, your content, and your most important pages. It is written in plain language specifically for AI models to read, helping them understand and accurately represent your brand when generating answers to relevant queries.
Is llms.txt an official standard?
Not yet - it is a convention rather than a formal technical standard. The specification was proposed in 2024 and is documented at llmstxt.org. A growing number of AI tools support it, including Claude. It does not have W3C or IETF standardisation, but its adoption is growing rapidly and implementing it now is low-risk with meaningful upside.
How do I create a llms.txt file?
Create a plain text or markdown file named llms.txt and place it in the root directory of your website so it is accessible at yourdomain.com/llms.txt. Include a short description of your business, who it is for, and links to your most important pages with brief descriptions. Keep it concise - under 500 words is ideal. No special syntax is required beyond basic markdown formatting.
Should I also have a pricing.md file?
Yes, if you want AI models to accurately represent your pricing or service tiers. A pricing.md file at yourdomain.com/pricing.md gives AI models a structured, always-current version of your pricing information. This is especially useful for service businesses where pricing is complex or contextual - you can explain nuance in a format AI models can parse and cite accurately.
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