- Free tools
- llms.txt Validator and Generator
FREE LLMS.TXT VALIDATOR AND GENERATOR
Check or build your llms.txt in seconds
Validate llms.txt markdown structure line by line against the llmstxt.org proposal, or generate a clean draft from the page URLs and descriptions you choose. No signup, and it runs in your browser.
Set expectations: llms.txt is a community proposal, not a web standard. No search engine uses it as a ranking signal and AI crawlers are not confirmed to read it. A valid file is tidy documentation, not guaranteed visibility.
- Line by line checks
- No signup required
- Nothing uploaded or stored
WHAT WE CHECK
Open yourdomain.com/llms.txt in a browser, copy everything and paste it here.
Checked in your browser. Your file is never stored.
Results
Paste an llms.txt file on the left and click “Validate llms.txt.” Results appear here.
HOW IT WORKS
From blank file to a valid llms.txt
No account, no crawler and no install. The tool reads the text you paste or the links you list and checks them against the structure the proposal defines.
Paste or build
Paste your live llms.txt, or switch to Generate and add your site name, summary and the pages a model should read first.
Fix what is flagged
Every issue is marked as an error, warning or note with its line number, and the file view highlights the exact lines.
Publish at the root
Copy or download the file, upload it so it resolves at
yourdomain.com/llms.txtand serve it astext/plainortext/markdown.
THE FORMAT
What a valid llms.txt looks like
Proposed by Jeremy Howard of Answer.AI in 2024, llms.txt is a plain markdown file with a fixed order of elements. Only the H1 is required.
# Acme Analytics > Privacy first web analytics for small teams. Acme runs as a hosted service and a self hosted Docker image. ## Docs - [Quick start](https://acme.example/start.md): Install - [API reference](https://acme.example/api.md): Endpoints ## Optional - [Changelog](https://acme.example/changelog.md)
One H1 with the site name
The first content line. A second H1 is an error.
Blockquote summary and context
A short summary in a blockquote, then any paragraphs or lists, with no headings before the first H2.
H2 sections of links
Each item is a markdown link with an optional note after a colon. A section named Optional holds links that can be skipped.
LLMS.TXT VS OTHER ROOT FILES
Where llms.txt fits next to robots.txt and sitemaps
llms.txt does not replace anything. It sits beside the files crawlers already rely on. To control which AI crawlers can fetch pages, use the robots.txt checker.
| Question | llms.txt | robots.txt | sitemap.xml |
|---|---|---|---|
| Main job | Curated reading list for models | Crawl permissions | Complete URL list |
| Format | Markdown | Directives | XML |
| Blocks or allows access | No | ✓ Yes | No |
| Used by Google Search | No | ✓ | ✓ |
| Confirmed AI crawler support | Not confirmed | ✓ Most major bots | Varies |
| Best fit | Docs, APIs, knowledge bases | Every site | Every site |
ADOPTION AND SEO
What is and is not known about llms.txt
- Google representatives have said Search does not use llms.txt, and AI Overviews rely on normal crawling and indexing.
- No major model provider has published a commitment to fetch llms.txt during training crawls or retrieval.
- Server log studies have found little to no crawler traffic requesting the file.
- Real usage is mostly on demand: developers paste an llms.txt URL into an assistant, and some documentation platforms, coding agents and MCP doc servers load it when asked.
For developer docs and APIs it is a cheap, useful addition. For marketing and ecommerce sites, crawlable HTML, structured data, clear entity information and content worth citing matter far more.
FAQ
llms.txt questions
Does llms.txt improve SEO rankings?
There is no evidence that it does. Google has said Search does not use llms.txt, and no major AI provider has publicly confirmed reading it during crawling. Treat it as a low cost experiment, not a ranking factor.
Where should the llms.txt file go?
At the root of your domain, for example https://example.com/llms.txt, served as plain text or markdown with a 200 status.
Is llms.txt the same as robots.txt?
No. robots.txt controls what crawlers may fetch. llms.txt grants or blocks nothing. It is a curated markdown index of the pages most useful to a language model.
Do linked pages need to be markdown?
No, but the proposal recommends offering a .md version of each linked page because clean markdown is cheaper for models to read than full HTML.
What is llms-full.txt?
A companion convention where the full text of your linked documentation is combined into one markdown file so a tool can load it in a single request.
Is my file uploaded anywhere?
No. Validation and generation run in your browser. Nothing is sent to a server or stored.
Check one file here. Audit AI crawler access across every page with SiteAuditLint.
llms.txt is one signal. Blocked AI crawlers, missing structured data and thin pages across a whole site need a crawl.
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