JSON ↔ XML Converter

JSON (JavaScript Object Notation) and XML (eXtensible Markup Language) are both data serialization formats used for storing and transporting structured data, but they have fundamentally different syntax and capabilities. JSON uses a compact syntax with objects ({key: value}), arrays ([]), strings, numbers, and booleans. XML uses a hierarchical tag-based syntax with elements (content), attributes, and a more verbose but more flexible structure.



Converting JSON to XML requires mapping JSON's data model to XML's element-based model. JSON objects become XML elements with child elements for each key-value pair. JSON arrays become repeated XML elements with the same tag name. JSON string, number, and boolean values become text content within elements.



The conversion handles edge cases: XML element names cannot start with numbers or contain certain special characters, so JSON keys that are invalid XML names must be transformed or wrapped. The root element (required in XML, not in JSON) is added during conversion. This tool performs the conversion using JavaScript's DOM manipulation, then serializes to formatted XML.

1. Legacy System Integration
Older enterprise systems and SOAP web services often require XML format for data exchange. Modern APIs and services typically return JSON. Converting JSON responses from REST APIs to XML enables integration with legacy systems without rewriting either the modern API or the legacy integration, acting as a translation layer.



2. Configuration File Migration
Some application frameworks use XML configuration files (Spring, Ant, Maven) while others use JSON (Node.js, many modern frameworks). Converting between formats when migrating applications reduces manual transcription errors and ensures structural correctness during the migration process.



3. Data Transformation Pipelines
ETL (Extract, Transform, Load) pipelines that process data from multiple sources may receive JSON from APIs and need to output XML to downstream systems. Having a reliable converter as part of the transformation step ensures clean, valid XML output from JSON input data.



4. XSLT and XML Processing
XSLT (eXtensible Stylesheet Language Transformations) is a powerful language for transforming XML documents. When working with XSLT processors or learning XSLT, having JSON data converted to XML allows you to use the full XML processing ecosystem (XPath, XSLT, XMLSchema) on data that originates in JSON form.



5. Documentation and Specification
Technical documentation sometimes needs to represent data structures in XML format (for WSDL specifications, XSD schemas, or XML-based documentation standards). Converting sample JSON data to XML provides concrete examples for XML-format documentation.

• Verify element names: JSON keys are arbitrary strings; XML element names have restrictions (cannot start with numbers, cannot contain spaces or most special characters). Review the output for any automatically sanitized element names.



• Arrays need a parent element: JSON arrays translate to repeated XML elements. The element name for array items is derived from the key name or defaults to a generic name. Verify that array items have meaningful element names in the output.



• XML is case-sensitive: Unlike JSON keys (which are compared by exact string match anyway), XML element names are case-sensitive and by convention use either camelCase, PascalCase, or kebab-case consistently. Consider normalizing case in your output.



• XML handles namespaces: Complex XML schemas may use namespace prefixes (xsi:, xs:). This basic conversion doesn't add namespaces. If the target XML format requires namespaces, additional processing after conversion will be needed.



• Validate the output: After conversion, validate the XML using an XML validator to ensure it is well-formed before using it in production systems that expect valid XML.