how to

How to check your llms.txt — does it exist, and is it reachable?

the short answer

To check your llms.txt, look for a file at your site's root (/llms.txt) and confirm it returns successfully rather than a 404; seo·check does this from a URL and reports whether the file exists and is reachable as part of your GEO readiness score.

llms.txt is the AI-era counterpart to robots.txt and sitemap.xml: a plain-text file at your site root that points AI agents and answer engines at the content you want them to use. It's a young convention, which means it's easy to ship one with a typo in the path, a wrong content type, or — most often — never ship it at all.

Confirming it's there and reachable is a small check that's easy to forget. seo·check handles it as part of the GEO read. Here's how to check your llms.txt and what a passing result looks like.

/llms.txtthe root path seo·check fetches to confirm the file exists
check a url →about seo·check

What 'valid' means for llms.txt

At its simplest, a working llms.txt is one that lives at your root path and returns successfully when fetched — not a 404, not a redirect to your homepage, not an HTML error page dressed up as text. Plenty of sites think they have one because the file is in the repo, while in production the path is wrong or the host never serves it.

seo·check checks the part that actually matters to an AI agent: can the file be retrieved at the expected location. A file that exists locally but 404s in production is, to an engine, the same as no file at all — and that's the failure this check is built to catch.

Where it fits in GEO readiness

llms.txt is one signal among several in the GEO score, alongside AI-crawler access in robots.txt and JSON-LD structured data. On its own it won't make or break whether you're cited, but it's a low-cost signal that tells AI agents which content you want surfaced, so it's worth getting right.

Because seo·check rolls it into the same report as crawler access and structured data, you see your llms.txt result in context — whether it's the missing piece or just one of several to tidy up. Fix it on your site, then re-run the check to confirm it's now reachable.

how it works

  1. 01

    paste your URL

    Enter any page on your site — seo·check derives the root and looks for /llms.txt.

  2. 02

    run the check

    It fetches the expected path and confirms whether the file is reachable.

  3. 03

    read the result

    See llms.txt marked present and reachable, or missing, within the GEO score.

  4. 04

    add and re-check

    If it's missing, publish an llms.txt at your root, then run the check again to confirm.

frequently asked

Where should llms.txt live?
At your site's root — for example, https://yoursite.com/llms.txt. seo·check looks for it there and reports whether it's reachable, the same convention as robots.txt.
My llms.txt is in my repo but the check says it's missing — why?
A file in the repo isn't the same as a file served in production. If the path is wrong, it redirects, or the host doesn't serve it, an AI agent gets a 404. seo·check checks what's actually fetchable, which is what an engine sees.
Do I need llms.txt to be cited by AI engines?
It's not strictly required, but it's a helpful, low-cost signal that points AI agents at your content. seo·check treats it as one part of GEO readiness, not a make-or-break on its own.
Does seo·check validate the contents of the file?
The core check confirms the file exists and is reachable at the expected path — the failure most sites actually hit. It's part of the free GEO score.

Published May 25, 2026 · Last updated June 13, 2026

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