The XML validator says my tags do not match

XML element names are case-sensitive and nesting must close in the reverse order they opened. Check for ` ` vs ` ` and crossed nesting like ` `.

Format XML online changed the whitespace in my file

pretty printers add structural indentation and may normalize spacing around declarations. The formatter keeps text and attribute escaping correct, while minify mode removes ignorable formatting whitespace and leaves mixed-content or whitespace-preserving subtrees alone when needed.

My XML root element is named `parsererror`

that is allowed. The validator only treats browser parser-error documents as failures, not ordinary XML documents that happen to use that element name.

My XML looks valid but will not parse

common causes are an unescaped `&`, missing quotes around an attribute value, multiple top-level elements, or stray characters before the XML declaration.

The output is equivalent but not identical to the input

formatting is serialization, not byte-for-byte preservation. Indentation, self-closing representation, and declaration spacing may differ, but the tool keeps the XML well-formed and text content intact.

Does this validate against XSD or DTD files?

this tool focuses on parsing and well-formedness. Schema validation is a separate step and requires the relevant schema plus a validator that supports it.

XML Formatter & Validator

Format, minify, and validate XML locally in your browser.

XML input

Output

Uses the browser XML parser only. Entity resolution, namespace handling, and compact output follow browser behavior for valid XML documents, while mixed-content or whitespace-preserving subtrees stay intact.