How to Use the llms.txt Validator on Tools.Town

This tutorial walks through a full pass of the free llms.txt Validator on Tools.Town — from empty textarea to a deploy-ready file.

1. Open the tool

Go to /tools/llms-txt-validator/. You will see two modes: Paste content and Fetch URL, plus Load example.

If you are new to the format, click Load example first. The sample shows a valid H1, blockquote summary, Docs section, and Optional section.

2. Paste mode (local draft)

1. Author llms.txt in your editor.
2. Select Paste content.
3. Paste the full file into the textarea.
4. Results update live.

Nothing is uploaded for paste validation — the parser runs in your browser.

3. URL fetch (staging or production)

1. Select Fetch URL.
2. Enter yourdomain.com or a full https://…/llms.txt URL.
3. Click Fetch & validate.

We normalize bare domains to https://domain/llms.txt, request the file through a same-origin proxy (to avoid browser CORS failures), then validate the returned text. If the host blocks us, returns 404, or times out, paste the body manually instead.

4. Read the result panel

Valid vs invalid

Valid means no error-severity issues (H1 present and first, list items are proper Markdown links, no illegal extra H1s / deep headings). You may still see warnings.

Invalid means fix errors before you treat the file as production-ready.

Stats chips

• H1 — product name extracted from #
• Sections / links — structure density
• Summary — whether a > block was found
• Absolute / relative — prefer absolute for portability
• Optional section — whether the special skippable H2 exists
• Size — push long dumps to llms-full.txt

Issue list

Each issue shows severity and often a line number (L12). Click into the textarea at that line:

Severity	Meaning
Error	Spec-breaking; fix before shipping
Warning	Allowed-ish but risky (relative URL, size, empty section)
Info	Heads-up (Optional section detected)

5. Fix the most common failures

1. First line not H1 — remove YAML, HTML, or prose above # Title.
2. List item without a link — change - Docs to - [Docs](https://…).
3. Second H1 — demote to ##.
4. Relative URL warning — expand to https://.
5. Missing summary — add > … after the H1.
6. Huge file — move body prose to docs pages or llms-full.txt.

For a from-scratch authoring checklist, see How to create llms.txt.

6. Re-validate and deploy

When errors are gone and warnings are acceptable:

1. Save as llms.txt at the web root.
2. Confirm live URL returns 200.
3. Run Fetch URL once more against production.
4. Ensure you did not Disallow the path in robots.txt — use the robots.txt Generator if you need rule help.

7. Keep learning

• Launch note: Introducing the llms.txt Validator
• Format deep dive: llms.txt guide
• vs crawler rules: llms.txt vs robots.txt
• Quality bar: best practices

Open the validator and run your file now.