JSON vs XML — Key Differences Explained
JSON and XML are the two dominant data interchange formats. Understanding their differences helps you choose the right format and convert between them effectively.
JSON ↔ XML Converter
Convert between JSON and XML formats. Handles nested objects, arrays, attributes, CDATA sections, and XML declarations.
About JSON ↔ XML Conversion
- JSON (JavaScript Object Notation) — lightweight data format with objects, arrays, strings, numbers, booleans, and null.
- XML (Extensible Markup Language) — hierarchical markup format with elements, attributes, namespaces, and CDATA sections.
- JSON → XML: Objects become elements, arrays wrap items in a configurable tag (default: "item"), primitives become text content. Root element name is configurable.
- XML → JSON: Elements become keys, repeated sibling elements become arrays, attributes use a configurable prefix (default: "@"), text content uses a configurable key (default: "#text").
- Swap button carries output to input for round-trip conversion.
- Everything runs in your browser — no data is sent over the network.
Syntax comparison
JSON uses curly braces for objects, square brackets for arrays, and colons for key-value pairs. It supports strings, numbers, booleans, null, objects, and arrays — 6 data types. XML uses opening/closing tags for elements, supports attributes on elements, and treats all content as text (no native data types). JSON is typically 30-50% smaller than equivalent XML due to the absence of closing tags.
// JSON (compact)
{"name": "Alice", "age": 30, "active": true}
<!-- XML (verbose) -->
<person>
<name>Alice</name>
<age>30</age>
<active>true</active>
</person>
<!-- XML with attributes (more compact) -->
<person name="Alice" age="30" active="true" />Performance and parsing
JSON parsing is faster in most languages because JSON maps directly to native data structures (JavaScript objects, Python dicts, Go maps). XML parsing requires DOM or SAX parsers, namespace resolution, and schema validation. For web APIs, JSON is 2-10x faster to parse. However, XML streaming parsers (SAX/StAX) handle very large documents more efficiently than loading entire JSON files into memory.
When to use each format
Use JSON for: REST APIs, web/mobile apps, NoSQL databases, configuration files, inter-service communication. Use XML for: SOAP services, enterprise integrations (EDI, HL7, FHIR), document formats (XHTML, SVG, RSS), systems requiring strong schema validation (XSD), mixed content documents, and legacy system interoperability. Many systems need both — hence the need for reliable conversion tools.
Frequently Asked Questions
Is JSON faster than XML?
For parsing, generally yes — JSON maps directly to native data structures in most languages. JSON documents are also smaller (no closing tags), reducing transfer time. However, XML streaming parsers can handle very large documents more memory-efficiently than loading entire JSON files.
Can XML do everything JSON can?
Yes, XML is more expressive than JSON. XML supports attributes, namespaces, mixed content, processing instructions, CDATA sections, and schema validation (XSD). JSON is simpler by design, which makes it easier to use but less capable for complex document structures.
Related Convert Tools
CSS Unit Converter
Convert between px, rem, em, pt, vw, vh, and % — single values or batch-convert entire CSS files with configurable base font size
Base64 Codec
Encode and decode Base64 strings with Unicode support
Color Converter
Convert colors between HEX, RGB, and HSL formats
Epoch Converter
Convert Unix timestamps to dates and back