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JSON vs XML

Comparing JavaScript Object Notation and Extensible Markup Language — which format should you use?

JSONXML
Full NameJavaScript Object NotationExtensible Markup Language
Extension.json.xml
MIME Typeapplication/jsonapplication/xml
Categorydatadata

JSON Pros

  • +Human-readable and writable
  • +Native support in every programming language
  • +Lightweight and fast to parse
  • +The standard for web APIs

JSON Cons

  • -No comments allowed in standard JSON
  • -No date type (dates stored as strings)
  • -No support for binary data
  • -Large files with deeply nested structures

XML Pros

  • +Human-readable and self-descriptive
  • +Platform and language independent
  • +Supports complex hierarchical data
  • +Extensive tooling and validation (XSD, DTD)

XML Cons

  • -Verbose — much larger than JSON or CSV
  • -Slower to parse than JSON
  • -Complex syntax rules
  • -Being replaced by JSON in many modern use cases

Use JSON when...

  • -REST API request/response data
  • -Configuration files
  • -Data storage and exchange
  • -Web application state management

Use XML when...

  • -SOAP web services
  • -Configuration files (Android, Maven, Spring)
  • -RSS/Atom feeds
  • -SVG graphics
  • -Office document formats (DOCX, XLSX)