When should I use XML instead of JSON?

Choose XML when standards, tools, or partners require it—SOAP, SAML, RSS, many enterprise buses, and document-centric models (mixed content, ordered elements). JSON wins for browser-first APIs and terse object graphs. For the same logical data in both worlds, keep one source of truth and convert carefully.

What is the difference between well-formed and valid XML?

Well-formed means the parser rules succeed: one root, properly nested tags, closed elements, legal entity references. Valid adds a schema (XSD, DTD, Relax NG) that constrains element names, order, and data types. You can pretty-print well-formed XML even before schema validation passes.

How do XML namespaces affect formatting and readability?

Namespaces partition element names to avoid collisions (`xmlns` declarations). Formatters typically preserve namespace bindings and can indent consistently across prefixed elements. Confusing output often means duplicate default namespace declarations or redefinition—fix declarations at the root before blaming indentation.

What is XSLT and does formatting help?

XSLT transforms XML into other XML, HTML, or text using pattern-matching templates. Readable source XML makes templates easier to reason about; the transformer ignores insignificant whitespace between elements in many cases, but text nodes inside elements are preserved—do not assume pretty-printing is always safe for mixed-content documents without testing.

Can I convert between XML and JSON losslessly?

Not always. XML attributes, repeated element names, and mixed content do not map 1:1 to JSON objects. Conventions like BadgerFish or bespoke mappers exist. For JSON-first data, start with [JSON Formatter](/json-formatter), then use dedicated converters; treat round-trips as a design exercise, not a given.

XML Formatter

v1.2.0

Use our free XML Formatter to clean, validate, and beautify XML data online. Instantly detect syntax errors, minify or expand structures, and view results in a readable tree format. Perfect for developers, API testers, and data analysts who need fast, reliable XML formatting.

Input

Output

Formatted XML will appear here

Input

Indent and inspect XML so integration bugs, namespace issues, and mismatched tags surface before they hit production traffic.

Read the full guide →

Frequently Asked Questions

When should I use XML instead of JSON?: Choose XML when standards, tools, or partners require it—SOAP, SAML, RSS, many enterprise buses, and document-centric models (mixed content, ordered elements). JSON wins for browser-first APIs and terse object graphs. For the same logical data in both worlds, keep one source of truth and convert carefully.
What is the difference between well-formed and valid XML?: Well-formed means the parser rules succeed: one root, properly nested tags, closed elements, legal entity references. Valid adds a schema (XSD, DTD, Relax NG) that constrains element names, order, and data types. You can pretty-print well-formed XML even before schema validation passes.
How do XML namespaces affect formatting and readability?: Namespaces partition element names to avoid collisions (`xmlns` declarations). Formatters typically preserve namespace bindings and can indent consistently across prefixed elements. Confusing output often means duplicate default namespace declarations or redefinition—fix declarations at the root before blaming indentation.
What is XSLT and does formatting help?: XSLT transforms XML into other XML, HTML, or text using pattern-matching templates. Readable source XML makes templates easier to reason about; the transformer ignores insignificant whitespace between elements in many cases, but text nodes inside elements are preserved—do not assume pretty-printing is always safe for mixed-content documents without testing.
Can I convert between XML and JSON losslessly?: Not always. XML attributes, repeated element names, and mixed content do not map 1:1 to JSON objects. Conventions like BadgerFish or bespoke mappers exist. For JSON-first data, start with [JSON Formatter](/json-formatter), then use dedicated converters; treat round-trips as a design exercise, not a given.