XML Validator
This XML validator checks that XML is well-formed: one root element, matching and properly nested tags, quoted attributes, and escaped special characters, with the line of the first error.
What you get
- Validate XML online: an XML syntax checker for unclosed or mismatched tags, unquoted attributes, unescaped & and <, and more than one root element.
- The line of the first error, so you can fix it quickly.
- XML lint in one paste: the first error is shown with its line, so you can fix files one problem at a time.
- Private and free: everything runs in your browser, nothing is uploaded, and there is no sign-up.
How each result is checked
- Checked for well-formedness with an XML validator; errors show the line.
What can't convert exactly
- This checks well-formedness, not a DTD or XSD schema.
Questions
Is my data uploaded?
No. Everything runs in your browser, in a background worker. Nothing is sent to a server.
Does it validate against an XSD or DTD?
No. It checks that the XML is well-formed, which every XML file must be. Validation against an XSD or DTD schema is a separate step done by tools that load that schema.
What is the difference between well-formed and valid XML?
Well-formed XML follows XML’s own rules (one root element, closed and properly nested tags, quoted attributes, escaped & and <). Valid XML is also well-formed and matches a DTD or XSD schema. This page checks well-formed XML.
How do I use the XML Validator online?
Paste your input or open a file on the left. The result appears on the right as you type, already checked; copy or download it. Nothing is uploaded: the XML Validator runs in your browser.