AEO
What is llms.txt, and does it actually do anything?
This comes up constantly, usually phrased as whether anyone has actually seen it do anything. Here is a straight answer.
What it is
A plain text file at the root of your site that explains what the site is, in language aimed at a machine rather than a person. It typically summarises the business and links to the pages most worth reading.
The reasoning is that a language model asked about you benefits from a clean summary rather than having to infer one from a navigation menu and a homepage full of marketing copy.
What is actually known about it
It is a proposed convention, not a standard. No major AI company has publicly committed to reading it or acting on it.
So anyone telling you it improved their AI visibility is describing something they cannot separate from everything else they did that month. That is not dishonesty necessarily, it is just not evidence.
Why we add one anyway
It takes about an hour, it cannot do harm, and the cost of being wrong is an hour.
There is also a side benefit that has nothing to do with machines. Writing the file forces you to produce one clear paragraph explaining what your business is and who it serves. Most businesses discover in the process that they do not have that sentence, and having it improves the website, the Google profile and how the team answers the phone.
What it will not do
It will not get you into answers you are otherwise absent from. If assistants have no corroborating sources for your business, a file on your own site describing yourself favourably does not fix that, for the same reason a self-written reference does not.
That problem is covered in why assistants name your competitors, and the fix is elsewhere.
Put it in perspective
If the choice is between writing an llms.txt and fixing a Google Business Profile that is half filled in, fix the profile. It is not close.
Do this one on a quiet afternoon when the important work is already done.
Common questions
What is llms.txt?
A proposed plain text file placed at the root of a site that summarises what the site is and points to its most useful pages, intended to make things easier for large language models. It follows the same idea as robots.txt, as a convention rather than a rule anyone is obliged to follow.
Does llms.txt actually work?
No major AI company has publicly confirmed that it reads or acts on the file. Anyone claiming measurable ranking gains from adding one is reporting a correlation they cannot isolate. It is a reasonable low-cost bet, not a proven mechanism.
Should I add an llms.txt file to my website?
It takes about an hour, it cannot hurt anything, and it forces you to write one clear summary of what your business does, which is useful on its own. Add it with modest expectations.
Is llms.txt the same as robots.txt?
No. Robots.txt controls what crawlers may access and is widely respected. Llms.txt describes and summarises content for language models, and has no established compliance behind it.