XML to JSON Converter — Two-Way Formatter

This two-way XML and JSON converter is intended for APIs, configuration files, test fixtures, data migration, documentation, and debugging. XML and JSON have different data models, so a transparent mapping is more useful than pretending every document can round-trip perfectly.

Mapping used by this converter

• The XML document element becomes the single top-level JSON key.
• Attributes use an @ prefix, such as @id.
• Repeated sibling tags become arrays.
• Plain leaf text becomes a JSON string.
• Text stored alongside attributes or child elements uses #text.
• A JSON array produces repeated elements when converted to XML.

JSON-to-XML validates element and attribute names, escapes text and attribute values, formats indentation, and adds an XML declaration. XML-to-JSON rejects malformed documents and DOCTYPE declarations before walking the DOM.

Some XML features have no lossless equivalent in ordinary JSON. Comments, processing instructions, entity declarations, CDATA boundaries, namespace semantics, and mixed text/element ordering are not preserved. Numbers, booleans, and null-like text read from XML remain strings because XML alone does not declare their JSON types. For schema-driven production transformations, use an XML-aware library with rules for your specific document format.

The parser and formatter run entirely in the browser. Data is rendered into text areas, never injected as live HTML, and is not sent to a conversion API.