Welcome to the authoritative validation home for WMO and ICAO data models. Schemas which are hosted from schemas.wmo.int can be validated here, including IWXXM, METCE, WMO Collect, and others.
This site uses local copies of XML Schema and Schematron files. XML files with WMO, ICAO, ISO, and OGC namespaces should validate quickly without any outgoing network connections. This site uses the authoritative XML validator library, Crux, to validate messages. Crux can also be used for validation as a Java library or can be used as a cross-platform command-line utility.
Validated XML files should always include an xsi:schemaLocation attribute on the root element