What is llms.txt, and does your site need one?
A file at the root of your site that hands AI assistants a curated map of your most important pages. It is cheap to add, it cannot hurt you, and adoption is still early — no major engine has confirmed they read it yet.
What it actually is
Think of it as a menu written for machines. Your sitemap lists everything you have ever published; llms.txt says "here are the pages that actually matter, and here is what each one is for." When an AI assistant tries to understand your business in a few seconds, it is the difference between handing someone a filing cabinet and handing them a one-page brief.
Why it matters
AI answer engines do not crawl the way Google does — they read a little and infer a lot. If the first things they find are your cookie policy and a paginated blog archive, that is the impression they form of your business. A good llms.txt puts your services, your pricing and your best explainers at the front of the queue, so the summary an assistant gives about you is the one you would have written yourself.
What good looks like
A file at yoursite.com/llms.txt that opens with your site name, gives a short plain-English summary of what you do, then groups your key links under simple headings — services, docs, about — with a line of description beside each. Ideally the site also advertises it in its response headers, so an assistant finds it without having to guess.
Being honest about it
This is helpful hygiene, not a ranking factor. Anyone promising you that llms.txt alone will get you cited by ChatGPT is overselling it. We flag it because the upside is real if adoption lands and the downside is nil — but if you only have budget for one thing, it is not this one.
Where most sites go wrong
Two failure modes. Either there is nothing there at all, or — more commonly, and worse — there is a file that exists but is thin, stale, or points at pages that have since moved. A stub with a heading and no links helps nobody. A dump of every URL you own defeats the entire point, because curation was the value. And an llms.txt written a year ago quietly tells an AI the wrong story about what your business does today.