DTD rule validation
DTD GA is live: validate XML directly against DTD for root consistency, element order, and occurrence constraints.
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Features Overview
DTD GA is live: validate XML directly against DTD for root consistency, element order, and occurrence constraints. DTD validation now supports ELEMENT models, ATTLIST attribute constraints, and internal ENTITY resolution.
Tool Description
Free XML validator online. Validate XML syntax, check XML against DTD or XSD schema rules, format documents, and convert XML to JSON for debugging API responses, feeds, and config files. Everything runs locally in your browser for private validation.
Capabilities Checklist
- Switch to the DTD Rule Validation tab and provide XML + DTD declarations.
- Run validation and fix issues using DTD_INVALID / DTD_MISMATCH feedback.
- Reuse the same error-code semantics in batch and API workflows for CI consistency.
- Ensure XML root matches DTD/DOCTYPE root declaration.
- Cover sequence, choice, repeat, EMPTY, ANY, mixed, and ATTLIST rules as needed.
- Treat DTD_INVALID and DTD_MISMATCH as fail-fast CI signals.
- Keep XSD path for cross-standard verification and gradual expansion.
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