How JSON Actually Works -Parsing, Serialization & Data Exchange Explained

Everyone uses JSON. Not everyone knows what actually happens under the hood when you call JSON.parse() or JSON.stringify().

What JSON is

JSON (JavaScript Object Notation) is a text-based format — not a binary format. That means when you "send JSON over an API", you're actually sending a plain string. The receiver parses that string back into a native data structure.

Serialization vs Parsing

Operation	Direction	Function
Serialization	Object → String	JSON.stringify()
Parsing / Deserialization	String → Object	JSON.parse()

What JSON supports

• Strings, numbers, booleans, null
• Arrays and nested objects
• Not supported: functions, undefined, Date objects, circular references

Why JSON beat XML

• No closing tags = smaller payloads
• Directly maps to native objects in most languages
• Human-readable without tooling
• Native browser support via JSON.parse()

Cross-language compatibility

Every major language has native JSON support:

import json
data = json.loads('{"name": "Imad"}')  # Python

const data = JSON.parse('{"name": "Imad"}')  // JavaScript

echo '{"name": "Imad"}' | jq '.name'  # Terminal

Further reading

Deep dive into JSON structure, parsing internals, and performance: How Does JSON Work — Complete Technical Guide

Need to work with JSON files? The JSON Merger and JSON Splitter tools handle the heavy lifting for free.