This JATS4R validator will validate an XML document against the appropriate JATS DTD (NISO JATS version 1.0, 1.1 or 1.2), plus recommendations that have been published on the JATS4R website.
The source code (MIT-licensed where applicable) is available for this user interface, the validator web service, the Schematron rules and the JATS DTDs.
The XML content will be sent to the JATS4R web service for validation. The doctype is logged, for usage metrics, but the rest of the XML document will not be stored.
Could you please indicate what you need support for so we can help you?