Validate your llms.txt file for free

See whether your llms.txt loads, what a crawler can read from it, and which links are broken. It also checks that robots.txt doesn't block the pages it lists.

Validate my llms.txtSee an example

Free. No signup, no card. We fetch the file ourselves.

What does an llms.txt validator check?

Four things: that the file loads at yourdomain.com/llms.txt, that it is laid out the way crawlers expect, that every link in it works, and that robots.txt doesn't block the pages it lists. A file with broken or blocked links wastes a crawler's time and gives it nothing back.

Use it with the free llms.txt generator: make the file, publish it, then check that it works.

Example validation result

Here is a check of a made-up vet clinic's file. Each line says what is fine and what needs fixing.

cedarlanevet.ca/llms.txt

Example

3 things to fix

  • File at /llms.txt

    Loads without errors and is served as plain text.

    Found

  • Title and summary

    Has a title and a one-paragraph summary.

    OK

  • Links that work

    1 broken link and 2 redirects.

    18 of 21

  • Broken link

    /services/puppy-classes was removed in the redesign.

    404

  • Blocked by robots.txt

    robots.txt blocks /pet-care-guides/, but llms.txt lists three pages there.

    3 links

  • Full URLs

    Every link starts with https://.

    OK

What to fix

  1. 1.Remove /services/puppy-classes, or point it at the page that replaced it.
  2. 2.Swap the two redirecting links for their final addresses.
  3. 3.Allow /pet-care-guides/ in robots.txt, or take those three links out of llms.txt.
  4. 4.Publish the new file and run the check again.
Example only. Cedar Lane Veterinary Clinic and cedarlanevet.ca are made up.

The report tells you whether a crawler can use your file, and which line to change if it can't.

Validate my llms.txt

How it works

  1. Step 1

    Enter your website

    We look for the file at the root of your domain, which is where crawlers look.

  2. Step 2

    We fetch and read it

    Title, summary, sections and every link, read the way a crawler reads them.

  3. Step 3

    Get a plain report

    What works, what is broken, and what to change.

What you get

Does the file load?

Whether /llms.txt exists, loads without errors, and is plain text rather than an error page.

Is it laid out right?

Whether it has a title, a summary, and sections a crawler can follow.

Do the links work?

Every link checked. Broken links and redirects are listed one by one.

Does robots.txt agree?

Whether llms.txt points to pages your robots.txt blocks. This is the most common problem, and the easiest to miss.

Who it's for

  • Anyone who published an llms.txt and wants to know it works.
  • Marketers checking a generated file before it goes live.
  • SEO and AEO consultants auditing client sites.
  • Developers checking the file after a redesign or a move.

What it often finds

  • The file returns a 404 and nobody noticed.
  • It loads as a web page instead of plain text.
  • Some pages it lists were moved or deleted.
  • It points to pages robots.txt blocks.

llms.txt, explained

What llms.txt is, and what it is not

llms.txt is a plain text file at the root of your site. It has a title, a short summary, and lists of links to your best pages.

It helps AI read you, but it can't make an assistant recommend you on its own. What it does is remove one reason to get you wrong: if AI can't find a clear statement of what you do, it guesses.

llms.txt and robots.txt often disagree

robots.txt says where crawlers may not go. llms.txt says where the good pages are. When they disagree, crawlers follow robots.txt and your llms.txt link is wasted.

This usually happens after a redesign, when a folder gets blocked and nobody updates llms.txt.

Worth checking:

  • Pages in llms.txt that robots.txt blocks
  • AI crawlers blocked in robots.txt
  • Test or staging pages left in either file

What a good llms.txt file has

  • Your business name as the title
  • A one-paragraph summary that states facts
  • Sections that group your pages
  • Full URLs that start with https://
  • A short note on what each page answers
  • Nothing that robots.txt blocks

The summary is the part most files get wrong. It is the line most likely to be quoted, so write it as plain facts.

After you validate

  1. 1.Fix every broken or redirecting link the report names.
  2. 2.Sort out each robots.txt conflict, one way or the other.
  3. 3.If the summary reads like an ad, rewrite it as plain facts.
  4. 4.Publish the new file and run the check again.

A working llms.txt makes you readable. Getting recommended is a separate job, and it is the one Sophyx does.

A working file doesn't mean AI recommends you

The validator tells you a crawler can read your site. It doesn't tell you what AI says when a customer asks. That check is free too: thirty prompts on ChatGPT and Gemini, re-checked every two weeks, no card. See where a competitor is named instead of you, then have us write and publish the fix on your own site.

See what AI says about you

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Questions people ask

What does an llms.txt validator check?
That the file loads at the right address, that it is laid out the way crawlers expect, that its links work, and that robots.txt doesn't block the pages it lists. A file that 404s or lists broken links is worse than no file.
Do I need llms.txt at all?
It is optional and its effect is modest. It points AI crawlers to your clearest pages. Publish it because it is cheap, not because it will change an AI answer on its own.
Where should the file live?
At the root of your domain: yourdomain.com/llms.txt. A file anywhere else won't be found.
How often should I re-check it?
After any redesign, site move or robots.txt change, and every few months otherwise. Links break quietly.
Will a valid llms.txt improve my AI visibility?
A little, at best. It removes a problem rather than giving you an edge. What changes an AI answer is a clear, correct page the AI reads, which is why the free AI visibility check is the more useful next step.

Check that your llms.txt works

Free, no signup, and it takes under a minute.

Validate my llms.txt
Validate my llms.txt
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