Reachability check
Whether the file exists at /llms.txt, returns a 200, and is served as plain text rather than as an HTML error page dressed up as a file.
Free AEO Tool
Validate your llms.txt
Paste or fetch your llms.txt and see whether it parses, what a crawler actually reads from it, and what is missing. It checks that the file is reachable, that its structure parses, that every link it lists resolves, and that it does not contradict your robots.txt. Free, no signup, no card.
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llms.txt validator
Enter your website URL. We fetch /llms.txt and check what a crawler reads.
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Building your report
Fetching /llms.txt...
Analysis progress10%
1Fetching /llms.txt...
2Parsing structure and headings...
What does an llms.txt validator check?
That the file is reachable at the expected path, that its structure parses, that the links it lists resolve, and that it is not contradicting your robots.txt. A file that 404s or lists dead URLs is worse than no file, because it spends a crawler's attention and returns nothing.
Pair it with the free llms.txt generator: generate the file, publish it, then validate that a crawler can actually use it.
What you get
Structure parse
Whether the Markdown parses, whether the title and summary a crawler looks for are present, and how many sections and links it finds.
Link health
Every URL the file lists, resolved. Dead links, redirect chains and bare domains are reported individually rather than as a count.
robots.txt conflict check
Whether your llms.txt points crawlers at paths your robots.txt tells them not to fetch. This is the most common real fault and the easiest to miss.
How it works
- 1
Enter your website URL
We look for the file at the root of your domain, which is where crawlers look.
- 2
We fetch and parse it
Structure, headings, summary and every link it lists, read the way a crawler would read them rather than the way they look in an editor.
- 3
You get a plain-language report
What works, what is broken, and what to change. No score to interpret on its own.
Who this is for
This free tool is useful for:
- Founders who published an llms.txt and have no way to tell whether it did anything.
- Marketers who generated a file from a tool and want it checked before it ships.
- SEO and AEO consultants auditing technical AI visibility for client sites.
- Agencies running a pre-launch check across several domains.
- Developers verifying the file after a migration, redesign or CMS change.
Common problems this tool helps you find
- Your llms.txt returns a 404 and nobody noticed.
- The file exists but is served as HTML, so nothing parses it.
- Some of the URLs it lists have since been deleted or moved.
- It points crawlers at paths your robots.txt blocks.
- Nobody has touched it since it was generated, and the site has changed since.
- You published it because someone said to, and have no idea whether it is correct.
Example validation result
After running the check, you may receive a result like this:
llms.txt Validation Website: https://example.com File URL: https://example.com/llms.txt Overall: 68/100 File status: - Reachable at /llms.txt: Yes - Content type: text/plain - Parses as Markdown: Yes - Size: 4.1 KB Structure: - H1 title present: Yes - Summary blockquote present: Yes - Section headings found: 6 - Links found: 34 Link health: - Resolving: 31 - Redirecting: 2 - Dead (404): 1 What needs attention: - One listed URL returns 404: https://example.com/old-pricing - Two URLs redirect, so a crawler spends two hops to reach the real page. - Your robots.txt disallows /resources/, but llms.txt lists four URLs under it. A crawler that respects robots.txt cannot fetch what this file points it at. - Three links use a bare domain rather than an absolute URL. Recommended fixes: 1. Remove or update the dead URL. A file listing dead links is worse than no file. 2. Point the two redirecting entries at their final destinations. 3. Resolve the robots.txt conflict, either by allowing /resources/ or by removing those entries from llms.txt. 4. Use absolute URLs throughout so there is nothing to resolve against. 5. Re-run this check after publishing the corrected file.
The report is written to be read rather than scored. The goal is not to grade the file. It is to tell you whether a crawler can use it, and exactly which line to change if it cannot.
GEO & SEO guides
Slide 1 of 3
GEO guide
What llms.txt is, and what it is not
llms.txt is a plain text file at the root of your domain that points a crawler at your clean, machine readable content. It is a Markdown document with a title, a short summary, and sections of links with descriptions.
Treat it as a signal rather than a guarantee. No file will make a model recommend you on its own, and anyone promising that is overselling it. What the file does is remove one excuse for being misread: if a model cannot find a clear statement of what you do, it will infer one.
Publishing it is cheap, which is the honest argument for having one. Getting it wrong is cheap too, which is the argument for checking it.
/llms.txt
# Your Brand > Short AI-readable summary ## Services * [Pricing](/pricing) * [About](/about)
What llms.txt is, and what it is not
llms.txt is a plain text file at the root of your domain that points a crawler at your clean, machine readable content. It is a Markdown document with a title, a short summary, and sections of links with descriptions.
Treat it as a signal rather than a guarantee. No file will make a model recommend you on its own, and anyone promising that is overselling it. What the file does is remove one excuse for being misread: if a model cannot find a clear statement of what you do, it will infer one.
Publishing it is cheap, which is the honest argument for having one. Getting it wrong is cheap too, which is the argument for checking it.
llms.txt and robots.txt disagree more often than you would think
The two files do opposite jobs. robots.txt tells a crawler where it may not go. llms.txt tells a crawler where the good content is. When they contradict each other, the crawler obeys robots.txt and your llms.txt entry is wasted.
This happens most often after a redesign, when a path is blocked for a good reason and the llms.txt file is not updated to match. Nothing warns you, because neither file knows the other exists.
A path listed in llms.txt that robots.txt disallows
A sitemap reference in one file and not the other
Staging or test paths left in either file after launch
AI crawlers blocked in robots.txt while llms.txt is published for them
What a good llms.txt file contains
An H1 with your brand name
A one-paragraph summary a model can lift and attribute
Sections grouping your pages by what they are for
Absolute URLs, so there is nothing to resolve against
A short description per link, saying what the page answers
Nothing listed that robots.txt blocks
When to use this
Use the Free llms.txt Validator when:
- After generating or hand-writing the file for the first time
- After a site migration, redesign or CMS change
- After editing robots.txt
- Before a client hand-off or a launch
- On a schedule, because links rot quietly
After you validate
- 1Fix any dead or redirecting URL the report names.
- 2Resolve every robots.txt conflict, in whichever direction is correct for that path.
- 3Rewrite the summary as a statement of fact rather than a pitch, if it reads like a pitch.
- 4Publish the corrected file and re-run the check.
A validated llms.txt is a floor, not a result. It makes you readable. Being recommended is a separate job, and it is the one Sophyx does.
A valid file does not make an assistant recommend you
Validation tells you a crawler can read your site. It does not tell you what an assistant says about you when a buyer asks. That is a different check, and it is free too: thirty prompts, re-checked every two weeks, no card. See which answers name a competitor instead of you, then have us write the correction and publish it on your own domain.
See what AI says about youMore free AEO & GEO tools
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Continue learning with guides, platform features, and AI visibility resources across the site.
FAQ
What does an llms.txt validator check?
That the file is reachable at the expected path, that its structure parses, that the links it lists resolve, and that it is not contradicting your robots.txt. A file that 404s or lists dead URLs is worse than no file.
Do I need llms.txt at all?
It is optional and its effect is modest. It is a signal that points a crawler at clean machine readable content. Publish it because it is cheap, not because it will change an answer on its own.
Where should the file live?
At the root of your domain, at /llms.txt. A file at a different path is a file nothing will look for.
How often should I re-check it?
After any migration, redesign or robots.txt edit, and otherwise on a schedule. Links rot quietly, and a file that was correct a year ago is not evidence that it is correct now.
Will a valid llms.txt improve my AI visibility?
On its own, marginally at best. It removes an obstacle rather than creating an advantage. What moves an answer is a clear, verifiable statement on a page the engine reads, which is why the free visibility audit is the more useful next step.
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