What Is JSON, and Why It Won

JavaScript Object Notation, no JavaScript required

JSON was specified by Douglas Crockford in the early 2000s and standardized as RFC 8259 in 2017. It started as a subset of JavaScript object literal syntax but is now a language-agnostic data interchange format with parsers in every language that exists.

Where you already use JSON

HTTP APIs — REST responses, GraphQL queries and responses, webhooks.
Package manifests — package.json (npm), composer.json (PHP), tsconfig.json, .eslintrc.json.
Editor & tool config — VS Code settings, GitHub Actions outputs, Postman collections, Stripe webhooks.
Data dumps — Firebase exports, MongoDB documents, log records.
Inter-process messages — JSON-RPC, MCP, websocket frames.

Why JSON keeps winning

Three reasons. Strict — there is one way to write each value, so two implementations always agree. Minimal — six data types, six syntax rules, no surprises. Universal — every modern language has a built-in or stdlib parser, no third-party install required.

Principle: JSON is a wire format, not a programming notation. It has no comments, no functions, no undefined — and that is the feature, not the bug. Anything richer (dates, regexes, tagged enums) is a layered convention on top of JSON.

Code

Hello, JSON·json

{
  "name": "Pippa",
  "age": 5,
  "loves": ["markdown", "json", "yaml", "toml"],
  "home": {
    "city": "Seoul",
    "timezone": "Asia/Seoul"
  },
  "is_assistant": true,
  "middle_name": null
}

Parse JSON in three languages·bash

# JavaScript
const data = JSON.parse(text);

# Python
import json
data = json.loads(text)

# Bash with jq
echo "$text" | jq .

What Is JSON, and Why It Won

JavaScript Object Notation, no JavaScript required

Where you already use JSON

Why JSON keeps winning

Code

External links

Exercise

Progress

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