XML Validator - Check XML Syntax Online Free

Validate XML syntax and well-formedness instantly. Detect errors with line numbers. Supports namespaces and DTD references. Free and private.

XML Input

Drop XML file here or browse

Enter XML and click Validate

Lines

Elements

0 B

Size

It checks for well-formedness: proper tag nesting, matching open/close tags, valid characters, proper attribute quoting, and correct XML declaration.

This tool validates well-formedness. For XSD schema validation, a server-side tool is needed due to browser limitations.

XML namespaces are parsed and validated. Namespace declarations and prefixes are checked for correctness.

Yes. All validation happens in your browser using JavaScript. No data is sent to any server.

Errors show the line number, column, and a description of what went wrong to help you fix issues quickly.

Well-formed means correct XML syntax. Valid means it also conforms to a DTD or schema. This tool checks well-formedness only.

The validator works with the encoding declared in the XML. If actual encoding differs from declaration, you may see parsing errors.

DTD references are parsed but not validated. The tool checks XML structure, not DTD compliance.

Standard entities (<, >, &, ", ') are supported. Custom entities require DTD definitions to resolve.

Yes. SOAP envelopes, RSS feeds, and other XML-based formats can be validated for well-formedness.