What Is JSON and How Does It Work?

JSON (JavaScript Object Notation) is a lightweight text format for representing structured data as key-value pairs, arrays, strings, numbers, booleans and null. It grew out of JavaScript object literal syntax but is now language-independent and used by virtually every web API.

Basic structure

A JSON document is either an object ({}) or an array ([]). Objects map string keys to values; arrays hold an ordered list of values. Values can themselves be objects or arrays, which is how JSON represents nested data.

Try pasting a sample document into our JSON Formatter to see the structure laid out visually.