FeatureXMLJSON
ReadabilityMore verboseMore concise
Human-friendlySomewhatHighly readable
Data TypesOnly text (XSD needed for types)Supports numbers, booleans, arrays
StructureHierarchicalKey-value (object-based)
Parsing SpeedSlowerFaster
Metadata SupportAttributes & elementsLimited metadata

Use XML when:

  • You need metadata (attributes).
  • Hierarchical document structures (e.g., legal documents).
  • Interoperability with legacy systems.

Use JSON when:

  • You need fast parsing and lightweight files.
  • Data exchange in APIs (REST, GraphQL).