Free JSON Formatter & Validator Online

JSON Formatter is a developer utility that parses, validates, and beautifies JSON data. JSON (JavaScript Object Notation) is the de facto standard for data interchange on the web — APIs return it, config files use it, and databases store it. When JSON is minified or poorly formatted, it becomes unreadable. This tool takes any JSON — whether it's a single line from an API response or a multi-megabyte config file — and outputs properly indented, syntax-highlighted text that's human-readable. It also validates the JSON and surfaces exact error positions when the input is malformed.

The formatter parses your JSON using the browser's native JSON.parse(). If parsing succeeds, it outputs the result through JSON.stringify() with 2-space indentation. If parsing fails, the error message includes the character position so you can locate the exact issue in your input.