JSON vs XML

JSON and XML are both formats for receiving data from a web server.

The JSON and XML examples below both define an “employees” object containing an array of three employee records:

JSON Example

{“employees”:[
  { “firstName”:“John”, “lastName”:“Doe” },
  { “firstName”:“Anna”, “lastName”:“Smith” },
  { “firstName”:“Peter”, “lastName”:“Jones” }
]}

XML Example

<employees>
  <employee>
    <firstName>John</firstName> <lastName>Doe</lastName>
  </employee>
  <employee>
    <firstName>Anna</firstName> <lastName>Smith</lastName>
  </employee>
  <employee>
    <firstName>Peter</firstName> <lastName>Jones</lastName>
  </employee>
</employees>

JSON is Like XML Because

Both JSON and XML are self-descriptive and human-readable.
Both JSON and XML are hierarchical, containing nested values.
Both can be parsed and utilized by various programming languages.
Both can be retrieved using an XMLHttpRequest.

JSON is Unlike XML Because

JSON does not require end tags.
JSON is more concise.
JSON is faster to read and write.
JSON supports arrays.

Key Difference:

XML requires an XML parser, while JSON can be parsed with a standard JavaScript function.

Why JSON is Better Than XML

Parsing XML is more complex compared to JSON.

JSON is directly parsed into a ready-to-use JavaScript object.

For AJAX applications, JSON is faster and simpler than XML:

With XML:

Retrieve an XML document.
Loop through the document using the XML DOM.
Extract values and assign them to variables.

With JSON:

Retrieve a JSON string.
Parse the JSON string using JSON.parse().