What makes an XML document well-formed?
A well-formed XML document must have a single root element, properly nested and closed tags, quoted attribute values, and escaped special characters (`&`, `<`, `>`).
Online XML Syntax Validator
Verify XML well-formedness and pinpoint unclosed tags or invalid characters by line number.
Instant Well-Formedness Check for XML
Our dual-engine validator combines `fast-xml-parser` validation rules with browser `DOMParser` diagnostics to catch every syntax defect.
Exact Line & Column Error Reporting
Immediately see the exact line number, column number, and error message when a closing tag is missing or an attribute quote is unclosed.
Common XML Validation Errors Explained
Detect unescaped ampersands (`&` instead of `&`), case-sensitive tag mismatches (`<Tag>` vs `</tag>`), and multiple root elements.
Frequently Asked Questions
Why does an unescaped & symbol fail XML validation?
In XML, `&` starts an entity reference. Raw ampersands in URLs or text must be written as `&`.
Can I validate XML Sitemaps before submitting to Google Search Console?
Yes, paste your `sitemap.xml` here to verify there are no broken tags or invalid entity characters before deploying.