llms.txt is a plain text file that sits at the root of your website, at yourdomain.com/llms.txt, and gives AI tools a clean, human-written summary of who you are, what you do, and which pages are worth reading. Think of it as a welcome packet for the robots. It takes about 20 minutes to write, it can't hurt anything, and most of what you've read about it is overselling what it does.
I'll tell you exactly what to put in yours. But first, the moment that convinced me the 20 minutes were worth it.
In March I was on a call with a client I'll call Dana, who runs an estate planning firm. Before we started her visibility work, I typed her firm's name into ChatGPT and asked what it knew. It answered confidently. It described a firm with the right name, the wrong city, and a list of services Dana stopped offering in 2021. Dana stared at the screen for a second and said, "So it's been introducing me as someone else."
Yes. That's exactly what it had been doing. Confused people don't take action, and it turns out confused AI tools don't send referrals either. They guess. And they guess from whatever signals your site gives them.
AI tools are already describing your business to potential clients. The only question is whether you wrote the description or they guessed at it.
What llms.txt Actually Is
You probably already have a robots.txt file. It tells search crawlers where they're allowed to go on your site. llms.txt is the newer cousin, proposed in late 2024, and it answers a different question. Robots.txt says "here's where you can go." llms.txt says "here's what this place means."
It's written in markdown, which is a fancy way of saying it's a text file with headings. No code. No plugins doing mysterious things. A heading with your business name, a sentence or two of summary, and a short list of your most important pages with one-line descriptions of each.
That's the whole format. The reason it exists: AI systems reading your website have to wade through navigation menus, cookie banners, and footer links to figure out what you actually do. llms.txt hands them the answer in 20 clean lines.
What Goes in Yours
Here's a trimmed version of the structure I use, with placeholder content:
A few rules I follow when I write these for clients:
- Write it like you'd explain your business to a smart stranger. No taglines, no marketing language. "We build HIPAA-compliant AI systems for healthcare teams" beats anything clever.
- List 8 to 12 pages, max. This is a highlight reel, not a sitemap. You already have a sitemap.
- Make it agree with your site. The summary in llms.txt, the description in your schema markup, and the first paragraph of your homepage should all tell the same story. Mismatched signals are what make AI tools hedge or guess.
- Include your location if local clients matter. "Based in Centerville, Ohio, serving the Dayton area" is the kind of plain fact AI tools love to repeat.
The Honest Part
Now the part most articles skip. No AI company has promised to read your llms.txt file. Adoption is uneven. Some crawlers fetch it, some ignore it, and nobody publishes a compliance report. If a consultant tells you llms.txt will get you cited by ChatGPT next week, they're selling you weather predictions.
So why do I still add one to every site I work on, including my own?
Writing the file is the cheapest clarity exercise in marketing. If you can't explain your business in 20 lines of plain text, the file was never the problem.
Three reasons. It costs 20 minutes. It can't hurt anything. And the discipline of writing it almost always exposes a bigger problem, because half my clients sit down to write their one-sentence summary and discover they don't have one. Dana's first draft took her four tries. The fourth try became her new homepage opener, and it's better than anything her old site said.
The file is one signal in a stack. Making your business visible to AI still depends mostly on schema markup, answer-first content, and consistent information across the web. llms.txt is the cover letter on top of that work, not a replacement for it.
llms.txt is cheap insurance plus a forced clarity exercise. It works as the top layer of a visibility stack. It does nothing as a substitute for one.
How to Write Yours in 20 Minutes
Here's the process, start to finish:
- Write the one-sentence summary first. What you do, who it's for, where you are. If this takes more than one draft, good. That's the exercise working.
- Pick your 8 to 12 most important pages. Services, about, pricing if you publish it, your best 3 or 4 articles. Skip the privacy policy.
- Write one plain line per page. Describe what a reader gets there, not what the page is called.
- Save it as llms.txt and upload it to your site root. On WordPress, that usually means your host's file manager. On most modern platforms, it's a static file in your project folder. Test it by visiting yourdomain.com/llms.txt in a browser.
- Check it against your homepage and schema. All three should agree on what you do. If they don't, fix the others to match the plain version, because the plain version is usually the true one.
One warning from experience: on some WordPress setups, plugins will generate a fake llms.txt page through the theme instead of serving a real file. Visit the URL and view the source. If you see your theme's HTML wrapped around it, it's not a real static file, and some crawlers will choke on it.
Frequently asked questions
Does llms.txt actually do anything?
Sometimes. Adoption among AI crawlers is uneven, and no company guarantees they read it. But the file costs 20 minutes, can't hurt your site, and forces you to write the plain-language summary of your business that your schema and homepage should already agree with. Treat it as cheap insurance plus a clarity exercise, not a magic switch.
Where does llms.txt go on my website?
At the root of your domain, so it loads at yourdomain.com/llms.txt. On most platforms that means uploading a plain text file the same way you'd add a robots.txt. On WordPress you may need a file manager plugin or your host's dashboard. It should be a real static file, not a page your theme generates.
What I'd Actually Do This Week
Open ChatGPT and ask it what it knows about your business, by name. Read the answer the way a potential client would. If it's accurate, you're ahead of most businesses I meet. If it's wrong, stale, or vague, write your llms.txt this week using the five steps above, then look at whether your homepage and schema are telling that same story.
And if the one-sentence summary fights you for four drafts the way it fought Dana, pay attention to that. The robots aren't your clarity problem. They're the mirror.