Paste some XML, compliant with HML Version that corresponds to your HML into the HML field and hit [ VALIDATE ].
Or, use the [ BROWSE ] button find an HML document on your computer.
A MIRING Results Report will appear below.
The MIRING HML Validator is a REST service, available to the public, hosted at miring.b12x.org/validator/ValidateMiring/
You can use this service programmatically using a POST request, with a single form parameter, "xml", containing the HML text.
Try this example using cURL:
$ curl -X POST --data-urlencode 'xml[]=<hml>...</hml>' https://miring.b12x.org/validator/ValidateMiring/
Validator source is on GITHUB