JSON Formatter & Validator

What is JSON?

JSON (JavaScript Object Notation) is a lightweight data interchange format that's easy for both humans and machines to read. It's the standard for REST APIs, configuration files, and data storage across nearly every programming language.

Common JSON validation errors

Trailing commas

JSON does not allow a comma after the last item in an object or array. {"name": "test",} is invalid — remove the trailing comma.

Single quotes

JSON requires double quotes for strings. {'name': 'test'} is invalid — use "name": "test" instead.

Unquoted keys

All object keys must be double-quoted strings. {name: "test"} is invalid — use "name": "test".

Missing commas

Every element in an array or property in an object must be separated by a comma. A missing comma between values will trigger an "unexpected token" error.

Unescaped special characters

Control characters, backslashes, and double quotes inside strings must be escaped. For example, a literal tab should be \t and a newline should be \n.

Keyboard shortcut

Press Ctrl+Enter (or Cmd+Enter on Mac) while the input is focused to format instantly.