My llms.txt file isn't validating — troubleshooting

CrawlPact’s llms.txt validator checks a small set of structural properties. Here’s what each issue means.

“No top-level Markdown heading found near the start of the file”

The validator looks for a line starting with # (a single #, a space, then text) within the first five lines of the file. A file that starts with plain text, an H2 (##), or a heading further down the file will trigger this. Fix: add # Your Site Name as the very first substantive line.

“The file is empty”

The file exists (CrawlPact received a response) but has no content. Fix: add actual content, or remove the file entirely if you don’t intend to publish one — an absent llms.txt is treated as informational, not an error.

No linked resources detected

The validator counts Markdown links in the form [label](url). If your file describes resources in plain text or a different format, they won’t be counted as linked resources. Fix: use standard Markdown link syntax for anything you want recognised as a linked resource.

The file returns a non-2xx status code

If your server returns an error status (404, 500, or similar) for /llms.txt, CrawlPact reports it as not found, the same as if the file didn’t exist. Confirm the file is actually deployed at the domain root and returns a normal 200 response.

Checking llms-full.txt separately

/llms.txt and /llms-full.txt are checked and reported independently — an issue with one doesn’t imply an issue with the other, and you don’t need to publish both.

See How to publish an llms.txt file for the full step-by-step guide.