Definition
llms.txt is a text file written in Markdown and placed at the root of a website that gives AI models a structured index of its content: a short presentation of the site, its priority pages with their URLs, and the business context needed to describe it accurately.
In plain English
Inspired by the robots.txt file that guides classic search engines, llms.txt is aimed at AI crawlers and the assistants behind them (ChatGPT, Claude, Perplexity). It holds a short description of your firm, the list of your key pages with their URLs, and possibly guidance on how to present your expertise. Jeremy Howard proposed the format in September 2024.
Unlike the XML sitemap built for traditional bots, llms.txt uses a plain text format that both people and language models can read directly. You control your firm's pitch, rank your practice areas, and steer AI toward your most relevant content: cornerstone articles, practice area pages, and practical guides.
For a law firm, it is a lever for AI citations. When someone asks ChatGPT for "a business lawyer in Atlanta," a model that reads your llms.txt can better understand your positioning and point to your resources rather than a competitor's. Keep expectations modest: Google says you do not need AI text files to appear in its AI features.
For a law firm
An intellectual property firm notices that Perplexity rarely cites it, despite a rich blog. By adding an llms.txt file at the root of its site, the firm explicitly lists its 8 flagship articles on patents, trademarks, and copyright, along with a one-line introduction: "Boston IP firm, 15 years of experience in counseling and litigation."
In the following weeks, the firm sees more citations in Perplexity's answers to queries like "how to protect a trademark in the US" or "pharmaceutical patent litigation." Qualified traffic from AI tools grows: visitors land directly on the pages listed in the llms.txt file, with a lower bounce rate than classic Google traffic.
The Hendy figure
Across the law firms we work with that have deployed an llms.txt file, we see on average a 15% to 25% increase in citations measured by AI tracking tools in the three months after it goes live.
The file takes about an hour to write, which is why we add it for clients, as an extra on top of open crawler access and answer-first pages.
Key takeaways
- llms.txt is a text file at the root of your site that guides AI tools toward your priority content.
- It complements, and does not replace, the XML sitemap, and it is written for language models.
- For a law firm, it is a lever for citations and qualified traffic from ChatGPT, Claude, or Perplexity, best added after crawler access is open.