How JSON Dethroned XML to Become the Web Standard

Until the early 2000s, XML (eXtensible Markup Language) held the throne of web data interchange. It dominated enterprise environments along with the SOAP protocol.

But what about now? Most REST APIs use JSON (JavaScript Object Notation). XML is mostly relegated to legacy systems or specific configuration files.

What exactly made JSON so attractive that it pushed XML aside to become the web standard?

1. Readability and Conciseness (Less is More)

The most intuitive difference is in their appearance. Let's compare the two formats representing the same data.

XML:

<user>
  <id>1</id>
  <name>John Doe</name>
  <email>[email protected]</email>
</user>

JSON:

{
  "id": 1,
  "name": "John Doe",
  "email": "[email protected]"
}

XML involves repetitive opening and closing tags (<id>...</id>), often resulting in the tags taking up more space than the actual data. JSON, on the other hand, uses curly braces {} and colons : to represent structure, making it much more concise and human-readable.

2. Language Native Support

As the name suggests, JSON's most powerful weapon is its compatibility with JavaScript.

Web browsers have built-in JavaScript engines. Since JSON data syntax is nearly identical to JavaScript object literals, it can be converted into a usable object instantly with a single JSON.parse() call, without needing complex parsers.

Handling XML in JavaScript, however, required traversing trees via a DOM parser, which was cumbersome. As frontend development shifted towards JavaScript, JSON's position became unassailable.

3. Explicit Data Types

In XML, everything is basically text. To distinguish between a number and a string, you often need a separate schema (XSD).

JSON, however, has built-in support for basic data types:

• String ("string")
• Number (123, 3.14)
• Boolean (true, false)
• Array ([...])
• Object ({...})
• Null (null)

This type support reduces ambiguity when exchanging data and helps prevent developer errors.

Conclusion

Of course, XML hasn't disappeared completely. Its metadata capabilities are still useful in fields like finance and healthcare where document structures are complex or strict validation is required.

However, for the web's core value of "exchanging data lightly and quickly," JSON has demonstrated overwhelming efficiency.

In the world of technology, "more complex and feature-rich" doesn't always win. Sometimes, like JSON, "simple and fit for purpose" changes the world.