About

The JSON to XML Converter is a specialized development tool designed to bridge the gap between two of the most popular data serialization formats: JavaScript Object Notation (JSON) and Extensible Markup Language (XML). While JSON has become the standard for modern web APIs due to its lightweight nature and close relationship with JavaScript, XML remains deeply entrenched in enterprise environments, configuration files, and protocols like SOAP.

Developers often face the challenge of migrating data between systems that speak different languages. For instance, a modern frontend might send data in JSON, but a backend legacy system might require XML input. This tool automates the transformation process, ensuring that the resulting XML is well-formed, properly escaped, and structurally equivalent to the source JSON object. It handles nested objects, arrays, and primitive data types, wrapping the result in a user-defined root element to satisfy XML's single-root requirement.

Formulas

The conversion process follows a recursive algorithm to map the flexible structure of JSON to the rigid hierarchy of XML. There is no single mathematical formula, but rather a structural transformation logic:

Step 1: Parsing. The input string is validated and parsed into a native JavaScript object/array using standard JSON parsers.
Step 2: Root Definition. Since valid XML requires exactly one root element, a wrapper tag (e.g., root) is initialized.
Step 3: Traversal & Mapping. The algorithm iterates through every key-value pair:
- If the value is a Primitive (string, number, boolean), it creates a text node wrapped in the key's tag: <key>value</key>.
- If the value is an Object, it recursively creates a parent tag and processes the children.
- If the value is an Array, the algorithm repeats the tag for each element in the array (e.g., <item>1</item><item>2</item>).
Step 4: Escaping. Special characters in data (like <, >, &) are replaced with entity references (e.g., <) to prevent XML parsing errors.

This ensures the output adheres to W3C XML standards while preserving the data hierarchy defined in the JSON input.

Reference Data

Feature	JSON (JavaScript Object Notation)	XML (Extensible Markup Language)
Syntax Style	Key-value pairs, curly braces	Tags, attributes, tree structure
Verbosity	Lightweight, compact	Verbose, text-heavy (closing tags)
Schema Support	JSON Schema (optional)	XSD, DTD (mature validation)
Parsing Speed	Fast (native in JS)	Slower (requires DOM/SAX parser)
Data Types	String, Number, Boolean, Array, Null	Strings (text content) only

Frequently Asked Questions

JSON arrays are lists of values, while XML relies on repeated elements. In this converter, an array under a key (e.g., "users": [...]) will result in repeated tags for that key in the XML output. For example, {"id": [1, 2]} becomes 12.

A valid XML document must have exactly one root element that contains all other elements. JSON does not have this restriction and can just be a list or an object. To make the output valid XML, we must wrap the JSON content inside a single parent tag.

Standard JSON does not differentiate between 'content' and 'attributes'—everything is a key-value pair. Consequently, this tool converts all JSON keys into XML elements (tags). It does not generate attributes (e.g., ) but rather nested elements (1).

XML has strict rules about special characters. Symbols like '', '&', '"', and ''' are automatically escaped (converted to <, >, etc.) to ensure the generated XML code does not break when parsed by other systems.