If you work in SEO you have heard this: “add an llms.txt file so AI can understand your site.” Is it true?
What is llms.txt?
It is a plain text file, placed on your website like robots.txt. The idea is to give AI tools a tidy summary of your site and its best pages.
What Google has said
- John Mueller (Google) said on the Search Off the Record podcast that an llms.txt file cannot help an AI decide which sites to show for a question. His reason: the file is written by the very site that wants to be chosen, so it cannot be trusted as a signal. He pointed back to normal web pages and internal links for discovery.
- He also said none of the AI services have said they use llms.txt, and that server logs show they do not even check for it.
- Gary Illyes (Google) said earlier, at a Search Central Live event, that Google does not support llms.txt and has no plans to.
- Google’s 2026 guide on AI search says plainly that you do not need llms.txt for its generative AI features. (We cover that guide in AEO, GEO and AI SEO explained.)
A mixed signal
Search Engine Journal points out that Lighthouse (Google’s site-checking tool, version 13.3) now checks for llms.txt by default and can flag errors in it. So Google’s own tools and Google’s own advice send mixed signals. Treat the Lighthouse check as a tool feature, not as proof that the file helps your rankings.
What the data shows
Ahrefs data reported by Search Engine Journal suggests the AI bots that matter barely fetch the file. Search Engine Land ran its own test on 10 sites; read their write-up if you want the detail.
What to do
- Do not spend a week on this. If you want to publish one, it takes minutes and is unlikely to hurt, but do not expect AI traffic from it.
- Spend that time on clear pages, internal links and original content.
- Do not pay anyone who sells llms.txt as an “AI ranking boost”.
One caveat: this could change if an AI company starts using the file. Nothing in the sources we read says that has happened.
