Paste your JSON to format it with proper indentation, minify it for production, or validate its syntax. Everything runs in your browser — nothing is sent to any server.
JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy for humans to read and write, and easy for machines to parse and generate. It is the most widely used format for transmitting data between a server and a web application.
JSON is built on two structures: a collection of key-value pairs (objects) and an ordered list of values (arrays). These universal structures make JSON compatible with virtually every programming language.
{}[]{name: "John"}
Keys must be in double quotes: {"name": "John"}
{"name": 'John'}
Strings must use double quotes, not single quotes
{"items": [1, 2, 3,]}
Trailing commas are not allowed in JSON
Formatting (pretty-printing) adds indentation and line breaks to make JSON human-readable. Use this during development, debugging, or when reviewing API responses.
Minifying removes all unnecessary whitespace to reduce file size. Use this for production configurations, API payloads, and storage where bandwidth or space matters.
Yes. All formatting, validation, and minification happens entirely in your browser using JavaScript. Your JSON is never sent to any server.
JSON is a text format that is a strict subset of JavaScript object syntax. Key differences: JSON requires double-quoted keys, does not allow functions or undefined values, and does not support trailing commas or comments.
No, the JSON specification does not support comments. Some tools like JSON5 or JSONC extend the format to allow comments, but standard JSON parsers will reject them.