XML Formatter Validator
Pretty-print, minify and validate XML instantly.
How to use
- 1 Paste your XML into the input box.
- 2 Choose an indent size, or tick Minify to collapse to one line.
- 3 Watch the formatted output update live as you edit.
- 4 Read any error message to find and fix unclosed or mismatched tags.
- 5 Copy the cleaned XML when the “Well-formed” badge appears.
About XML Formatter Validator
The XML Formatter Validator takes messy, single-line or inconsistently indented XML and rewrites it with clean, predictable structure so it is easy to read and diff.
Paste a config file, an API response, an RSS feed or a SOAP envelope and the tool re-emits the document with consistent indentation, one element per line, while preserving your attributes exactly as written.
If you need the opposite, the minify option collapses everything back onto a single line to save bytes.
Beyond formatting, it checks that the XML is actually well-formed.
As you type it walks the document with a small stack-based parser and flags the common mistakes that break real parsers: a tag that is never closed, a closing tag that does not match the element it ends, a stray closing tag with no opener, or more than one root element.
Each problem is reported with a specific, human-readable message that points at the offending tag, instead of a vague "parse error".
Comments, CDATA sections and the XML declaration are all recognised and kept intact.
This is a structural, well-formedness check rather than validation against a DTD or XSD schema, which is exactly what you want when you are quickly cleaning up a snippet.
Everything runs entirely client-side in your browser, so sensitive payloads never leave your machine and the tool keeps working offline once loaded.
FAQ
Does it validate against a schema (DTD/XSD)?
No. It checks structural well-formedness only — matched tags, a single root and proper nesting — which catches the most common XML errors without needing a schema.
Are attributes and comments preserved?
Yes. Attributes are kept exactly as written, and comments, CDATA sections and the XML declaration are retained in the formatted output.
Is my XML uploaded anywhere?
No. All parsing and formatting happen locally in your browser. Nothing is sent to a server or stored.