XML Validator Online

Validate XML well-formedness: proper tag nesting, attribute quoting, encoding, and single root element.

How to Use

  1. 1

    Paste XML

    Paste your XML document into the editor.

  2. 2

    Validate

    Click Validate to check well-formedness.

  3. 3

    Fix errors

    Error messages include descriptions to help fix issues.

FAQ

What is well-formed XML?

Well-formed XML must have: exactly one root element, properly nested opening/closing tags, quoted attribute values, correct character encoding declaration, and no overlapping elements.

Does this validate against XSD or DTD?

Currently this validates well-formedness (syntax) only. Schema validation (XSD/DTD) requires server-side processing and is not yet supported in this browser-based tool.