The llms.txt File: The Fastest Win for AI Visibility

llms.txt is a plain text file you drop in your domain root that tells AI models exactly what your business does, who you serve, and how to describe you — and most businesses don't have one.

It's the fastest implementation win on our fix list. Here's what it is and how to do it.

What llms.txt does

Similar to robots.txt (for search crawlers) and humans.txt (for developers), llms.txt is a structured hint file for AI language models. It provides context about your site that LLMs can use when generating answers.

Think of it as writing your own AI pitch: "Here is what I do, here is who I serve, here is how to accurately describe me."

What to put in it

A useful llms.txt is simple and factual. Include: business name, type, location, list of services, one sentence describing your unique value, and contact information. The more specific you are, the better. "Residential plumber" is weaker than "residential plumber specializing in bathroom renovations and emergency repairs in Burlington, ON."

Where to put it

Create the file at yourdomain.com/llms.txt — the domain root. It should be publicly accessible, no login required. Most web hosts let you drop files directly into the public folder.

Does it actually work?

Our Signal Check data shows a measurable improvement in Perplexity and Claude citations for sites with a well-formed llms.txt versus those without. ChatGPT's improvement is less consistent, but the file costs nothing to add.

It's 15 minutes of work. We recommend it as the first fix for any business with a score below 7.