XML Formatter guide
Validate XML syntax and indent elements into a readable structure while preserving attributes, comments, CDATA, and mixed-content sections.
What this tool does
The XML Formatter sends the supplied text to the browser's XML DOMParser. Invalid markup produces a parser message instead of formatted output. Valid documents are rebuilt with two-space indentation for nested element structures. Attribute values and text are escaped when they are serialized, and common XML nodes such as comments, processing instructions, document types, and CDATA sections are retained.
Whitespace can carry meaning in XML. When an element mixes text with child elements, the formatter serializes that complete element without inserting decorative line breaks inside it. This cautious behavior avoids changing prose-like content such as XHTML sentences where spaces around inline elements matter. Element-only structures are expanded across lines for easier inspection.
Formatting validates well-formed XML syntax; it does not validate a document against an XSD, DTD business rules, or an application's required fields. It also does not beautify malformed XML, repair mismatched tags, transform data with XSLT, or confirm that namespaces have the meaning an external service expects.
How to use it
- Paste a complete XML document or a single root element.
- Select Validate and format.
- If an error appears, inspect the location and correct the source markup.
- Review the formatted structure and mixed-content areas.
- Copy the result or download it as an
.xmlfile.
Before replacing a production file, compare the formatted result with the original in the software that consumes it. Preserve backups when whitespace, digital signatures, canonicalization, or exact byte sequences matter.
Benefits
- Validates with the browser's standards-based XML parser
- Adds readable two-space indentation
- Preserves comments, CDATA, attributes, and processing instructions
- Avoids re-indenting mixed text and element content
- Copies or downloads the formatted document
- Performs parsing and export locally
Important limitations
The tool does not load a schema or confirm domain-specific validity. External entity behavior and parser diagnostics can differ across browsers, so do not use this page as a security sanitizer. Never process untrusted XML and then assume it is safe solely because it is well formed. Applications should use hardened server-side XML settings appropriate to their environment.