Article · Wikipedia archive · Last revised May 27, 2026

XML validation

XML validation is the process of checking a document written in XML to confirm that it is both well-formed and also "valid" in that it follows a defined structure. A well-formed document follows the basic syntactic rules of XML, which are the same for all XML documents. A valid document also respects the rules dictated by a particular DTD or XML schema. Automated tools – validators – can perform well-formedness tests and many other validation tests, but not those that require human judgement, such as correct application of a schema to a data set.

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XML validation is the process of checking a document written in XML (eXtensible Markup Language) to confirm that it is both well-formed and also "valid" in that it follows a defined structure. A well-formed document follows the basic syntactic rules of XML, which are the same for all XML documents.1 A valid document also respects the rules dictated by a particular DTD or XML schema.2 Automated tools – validators – can perform well-formedness tests and many other validation tests, but not those that require human judgement, such as correct application of a schema to a data set.

Standards

  • OASIS CAM is a standard specification that provides contextual validation of content and structure that is more flexible than basic schema validations.
  • Schematron, a method for advanced XML validation.

Tools

References

References

  1. "Well-Formed XML Documents". Extensible Markup Language (XML) 1.1. W3C. 2004.
  2. "Constraints and Validation Rules". XML Schema Part 1: Structures Second Edition. W3C. 2004.
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