JSON Guide
What is JSON?
A practical introduction to JSON syntax, values, objects, and arrays.
A small, universal data format
JSON stands for JavaScript Object Notation. It is a text format used to exchange structured data between browsers, servers, command-line tools, and applications.
Although its syntax began in JavaScript, JSON is language-independent. Nearly every modern programming language includes a JSON parser and serializer.
The six JSON value types
JSON values can be objects, arrays, strings, numbers, booleans, or null. Objects associate quoted names with values, while arrays preserve an ordered sequence of values.
JSON does not include comments, undefined, functions, dates, or special number values such as NaN and Infinity.
Strict syntax matters
Property names and strings require double quotes. Items are separated by commas, but the final item cannot have a trailing comma. These rules make documents predictable across languages.