XML DTD Validator

This tool performs DTD-based validation of XML documents to confirm structural conformance with the associated DTD. It targets developers, data engineers, QA teams, and content authors who manage XML payloads or XML-driven workflows. By validating against element definitions, content models, and attribute constraints, it helps detect misplacements, missing elements, and invalid attributes before data is exchanged or stored. The validator supports both internal and external DTD subsets, handling inline DTDs and URL-referenced subsets when permitted. Conceptually, the process involves parsing the XML for well-formedness, resolving the DTD, and applying the DTD grammar to verify the instance meets the defined rules. The output provides a detailed report with line and column positions, enabling precise remediation. Unique value lies in precise error localization, compatibility with automated pipelines, and a focus on correctness rather than transformation, making it especially suitable for CI validation and data workflow quality. Core features include input fields for the XML document and DTD reference (inline or URL), an option to enable external subset resolution, and a comprehensive validation report suitable for automation. Typical use cases include validating configuration files, data exchange documents, and XML-based documentation prior to ingestion or publication.