Validate llms.txt File Online
Publishing an invalid llms.txt is worse than publishing none at all — a malformed file may cause LLM crawlers to silently skip your site or misparse your content inventory. Validating before you deploy catches issues early.
This tool accepts your llms.txt via paste or file upload and runs a full spec-conformance check in your browser. It reports errors (spec violations that will cause parsing failures), warnings (best-practice deviations), and informational notes (suggestions for richer content) — all with line numbers and suggested corrections.
There is no file size limit and no server involved. Paste from clipboard, drag-and-drop a file, or type directly — the validator responds in real time.
How to use
- Paste your llms.txt content into the input area on the main tool page, or drag and drop your file.
- Click Validate — errors and warnings appear instantly with line numbers and fix suggestions.
- Fix the flagged issues and re-validate until the green Valid llms.txt badge appears.