JSON vs. XML: What's the Difference?

JSON and XML both represent structured data, but differ significantly in syntax, verbosity, and typical use cases.

Syntax differences

XML uses opening and closing tags for every element (`<name>Ada</name>`), plus optional attributes on tags. JSON uses key-value pairs directly (`"name": "Ada"`). This makes JSON noticeably more compact for the same data, since XML repeats each element name twice — once to open and once to close it.

What XML can do that JSON can't

XML natively supports attributes on elements, mixed content (text interleaved with child elements), namespaces, and a rich schema/validation ecosystem (XSD, DTD). These features make XML well-suited to certain document-centric formats, like complex publishing formats, where mixed text and markup matters.

Why JSON dominates modern APIs

For typical application data — objects, lists, and simple values — JSON is smaller, easier to read, and maps more directly onto data structures already used inside application code. Nearly every modern language has built-in or trivially available JSON parsing, while XML parsing typically requires more setup and produces a more complex object model (a DOM tree) to work with.

When you'll still see XML

XML remains common in legacy enterprise systems, SOAP-based web services, certain document formats (like DOCX and SVG, which are XML under the hood), and configuration in some Java-based tooling. Knowing how to convert between the two remains a practical, everyday skill.