XML Validator
Check whether XML is well-formed using the same parser as the XML converters.
This tool runs entirely in your browser. Your files are never uploaded to a server.
Valid: The input is well-formed XML.
- Root element: <note>
- Total elements: 3
- Root element has no attributes.
Clear the entered value before starting another check. Validation runs locally and does not check against any external registry, server, or account.
What this tool does
Checks whether XML text is well-formed: correctly nested and closed tags, valid attribute syntax, and exactly one root element.
How to use it
Paste or type XML. The checker reuses this site's XML parser — the same one behind the XML ↔ JSON converters — and reports the root element, total element count, and any attributes on the root.
Example
Entering <note><to>Ada</to><from>Bob</from></note> returns valid, reporting note as the root element with 3 total elements.
Validation
Tags must open and close in matching pairs with exactly one root element; attribute values must be quoted and attribute names cannot repeat within a tag; comments, CDATA sections and processing instructions are recognized and skipped, while DOCTYPE declarations are rejected outright for safety.
How to interpret the result
A valid result confirms the XML is well-formed and safe to parse — it does not validate the document against an XML Schema, DTD, or any application-specific structure requirements.
Limitations
This checker rejects any DOCTYPE declaration rather than resolving external or internal entities, so a document that depends on one will fail here even if some parsers would accept it. For pretty-printed output, use the XML Formatter; to convert to JSON, use the XML to JSON Converter.
Privacy
All processing uses local browser APIs and this tool does not upload the values you enter.
Frequently Asked Questions
- What does XML Validator do?
- Checks whether XML text is well-formed: correctly nested and closed tags, valid attribute syntax, and exactly one root element.
- How does it handle invalid input?
- Tags must open and close in matching pairs with exactly one root element; attribute values must be quoted and attribute names cannot repeat within a tag; comments, CDATA sections and processing instructions are recognized and skipped, while DOCTYPE declarations are rejected outright for safety.
- Is entered data uploaded?
- All processing uses local browser APIs and this tool does not upload the values you enter.