XML Validator
The XML validator confirms that a document is well-formed and, when it is not, reports the parser error with its position. It also summarises the document: root element, element count and maximum nesting depth.
XML to validate
Validation result
Your result will appear here.
Not sure where to start? Use Load example.
Results update automatically and are calculated on your device. Nothing you type is sent to a server.
Runs in your browser. Processing happens entirely in your browser. Nothing you enter is sent to Delimiter.live.
How to use the XML Validator
- Paste the XML document you want to check.
- A valid document returns a structure summary; an invalid one returns the parser error and its position.
- Fix the reported problem and validate again.
Example
Input
<a><b></a>
Output
Not well-formed Mismatched tag: expected </b> but found </a>.
Common use cases
- Finding the unclosed tag in a document a parser rejected.
- Checking a generated feed before publishing it.
- Confirming an SVG or configuration file is well-formed after editing.
Limitations and things to watch for
- This checks well-formedness only — that tags are balanced, attributes are quoted and the document has a single root. It does not validate against a DTD, XSD or RelaxNG schema.
- Browser parsers report the first error and stop, so fixing one problem may reveal another.
Frequently asked questions
What does "well-formed" mean?
That the document follows XML syntax rules: one root element, every tag closed and correctly nested, attributes quoted, and reserved characters escaped. It is a lower bar than schema validity.
Can it validate against my XSD schema?
No. Schema validation needs the schema itself and a validating processor, which is beyond what a browser tool can do reliably. This tool checks well-formedness only.
Why does it only show one error?
Once an XML parser hits a structural error it can no longer trust the rest of the document, so it stops. Fix the reported error and run it again.