If you've read anything about AI search lately, you've probably seen llms.txt described as "robots.txt for AI". That's not quite right — and the difference matters when deciding whether to bother.
What Is llms.txt?
llms.txt is a proposed standard, first published in 2024, for a plain-text Markdown file at the root of your website (yoursite.com/llms.txt). It gives AI tools a short, curated summary of your site and links to the pages that matter most.
Unlike robots.txt, it doesn't allow or block anything. It's closer to a table of contents written for machines.
What Goes In It?
The format is simple:
# Your Business Name
> One or two sentences on what you do, for whom, and where.
## Services
- [Service name](https://yoursite.com/service): one-line description
## Guides
- [Article title](https://yoursite.com/blog/article): one-line summary
## Optional
- [About](https://yoursite.com/about): who we areYou can see ours at quadcydle.com/llms.txt — it's generated automatically from the same content as our menus, so it never goes out of date.
Does Anyone Actually Use It?
This is where honesty matters. Support is uneven:
- Some AI coding tools and documentation assistants read llms.txt files.
- Major AI search products haven't committed to using it as a signal, and Google has said it doesn't need it for Search.
- There's no evidence that having one improves rankings or citations on its own.
So treat it as a low-cost, low-risk extra — not a strategy.
Should You Add One?
Yes, if it takes you ten minutes and you'll keep it up to date. It forces a useful exercise: deciding which pages actually represent your business.
Don't prioritise it over the things that demonstrably matter: letting AI search crawlers in (see should you block AI crawlers?), having content in the HTML rather than hidden behind JavaScript, clear answers on your pages, and accurate structured data.
Common Mistakes
- Listing every page. The point is curation. Link your key services, guides and contact page.
- Letting it go stale. A file pointing to deleted pages is worse than none. Generate it from your CMS if you can.
- Marketing copy. Write the summary like a factual description, not a slogan.
Want to see whether your site has one — and what else AI tools see? Try our free AI Readability Checker, or read the full AI-readability checklist.