JSON vs XML
JSON and XML both represent structured data as text, but JSON has become the dominant choice for web APIs while XML remains common in enterprise, document, and configuration contexts where its stricter structure and metadata support matter.
For web APIs and anything JavaScript touches, JSON's simplicity and native fit with the language make it the default choice today.
Side by side
| JSON | XML | |
|---|---|---|
| Readability | Concise, less visual clutter | More verbose due to closing tags |
| File size | Smaller for the same data | Larger due to tag repetition |
| Attributes/metadata | No native concept of attributes | Native attribute support alongside element content |
| Schema validation | JSON Schema (less universally adopted) | XSD/DTD (mature, widely adopted standard) |
| Namespaces | Not supported | Supported - useful for combining vocabularies |
| Common use case | Web APIs, config files, JavaScript-heavy apps | Document formats (like Office files), SOAP APIs, enterprise systems |
The verdict
For web APIs and anything JavaScript touches, JSON's simplicity and native fit with the language make it the default choice today. XML still earns its place where strict schema validation, attributes, namespaces, or document-oriented structure genuinely matter - it hasn't disappeared, it's just been pushed into the contexts where its extra structure pays for itself.
Try it yourself
Frequently asked questions
01Is XML obsolete?
No - it's simply less common for new web APIs than it once was. It remains standard in many enterprise systems, SOAP-based APIs, and document formats.
02Can JSON represent everything XML can?
Mostly, but not natively - JSON has no built-in concept of attributes or namespaces, so representing XML-style metadata in JSON requires a convention (like prefixing keys with @) rather than native support.
03Which is faster to parse?
JSON generally parses faster and with less overhead, partly because its grammar is simpler and partly because most languages have highly optimized native JSON parsers today.