Is this XSD validator really free?

Yes. It is completely free and open source, with no sign-up, no limits, and no ads. Validation runs entirely in your browser via WebAssembly.

Are my XML and XSD files uploaded to a server?

No. Everything runs client-side using Apache Xerces-C++ compiled to WebAssembly. Your files never leave your device.

Does it support multi-file schemas with xs:include and xs:import?

Yes. Drop multiple .xsd files, pick the entry schema, and includes/imports between them are resolved during validation.

Free XSD Validator — Validate XML Against XSD Online

XSD schema files

Drop .xsd files here or browse

XML document

Drop .xml document here or browse

document.xml

Private by design

Most online XSD validators upload your files to a server. This one doesn't: Apache Xerces-C++ runs as WebAssembly inside your browser tab, so sensitive schemas and documents stay on your machine.

Real Xerces validation

The same battle-tested Apache Xerces parser used in enterprise systems for decades — full XSD 1.0 structural and datatype validation with precise line/column diagnostics.

Multi-file schema projects

Drop a whole set of .xsd files at once. Pick the entry schema and xs:include / xs:import references between them are resolved automatically.

Powered by Apache Xerces-C++ compiled to WebAssembly — validates XSD 1.0. XSD 1.1-only features (xs:assert, conditional type assignment, open content) aren't validated: Xerces-C++ itself has never implemented XSD 1.1.

When you edit the text area, it auto-validates in real time.

PROBLEMS