What Is JSON and How to Read It
JSON is the data format behind most APIs. Learn its structure, common errors and how to format it.
Published 2026-01-20
Short answer
JSON (JavaScript Object Notation) is a text format for storing and exchanging data using key-value pairs and arrays. It is easy for humans to read and for machines to parse.
JSON structure
JSON has objects (key-value pairs in braces), arrays (lists in brackets), and values that are strings, numbers, booleans, null, objects or arrays. Keys and strings use double quotes.
Common JSON errors
Trailing commas, single quotes, unquoted keys and unmatched brackets are the most common mistakes. A JSON formatter validates and points to the error line.
Formatting and minifying
Format (beautify) JSON to read it, and minify it to save space for transport. Both are useful in different stages of working with data.