What is llms.txt?
Does llms.txt work?
For Google Search, no. Google's guidance on optimising for generative AI search says you don't need machine-readable files, AI text files or Markdown to appear in Search, because Google Search doesn't use them1. The same guidance says you don't need to break content into small pieces, write in a special way for AI, or add special markup1.
For other AI services, Google's page only says it is fine to keep such files for "other services or systems that use these files"1. It does not name any. We have no evidence either way. A claim that "AI assistants use it" is worth something only if it names the assistant and shows how it was checked.
Why does it matter for your budget?
The file is small and cheap to add. The risk is not the file. The risk is reporting it as progress.
An hour spent on llms.txt is an hour not spent on work you can measure. Our view: a task earns a line in a monthly report when someone can say what it was meant to change and how that will be seen.
Easily confused with
llms.txt vs GEO (generative engine optimisation)
The practice of optimising content for visibility in answers from generative AI systems. llms.txt is one file that is sometimes offered as part of it. The term is used broadly and inconsistently, so ask what is meant.
llms.txt vs AI Overviews
AI-generated summaries in Google Search. They are a Google Search feature. llms.txt is a proposal for a file.
llms.txt vs AEO, GEO and SEO
Three labels that overlap more than their sales pages suggest. The fuller picture is in AEO vs GEO vs SEO.
Buzzword alert
"We have added llms.txt, so you are ready for AI search"
Usually means: a file was published and ticked off a list.
Ask: what should be different now that it is live?
"llms.txt is the new robots.txt"
Usually means: an analogy that makes a text file sound like a control.
Ask: what does this file actually control?
FAQ
Do I need an llms.txt file for Google Search?
No. Google's documentation says Google Search ignores these files, and that creating one is "completely fine" but will neither harm nor help your visibility or rankings there1.
Is optimising for AI search different from SEO?
Google's guidance says optimising for generative AI search is still SEO1. If someone sells you a separate AI-only programme, ask what it does that normal SEO does not.
Can llms.txt hurt my site?
Not in Google Search: Google says it neither harms nor helps there1. The practical cost is the time spent and the claims made about it.
Sources
Let’s find what’s actually working.
Next step. Want to know where you stand in search and AI answers? See our SEO and AI visibility service.