JSON Formatter & Validator - Format and Validate JSON

JSON (JavaScript Object Notation) is a lightweight data interchange format. It is readable for both humans and machines. It is based on a subset of the JavaScript programming language and is used in almost all modern web applications, APIs, and configuration files. It supports the data types: strings, numbers, objects, arrays, boolean, and null values.

Formatting (beautify/pretty-print) adds spaces, indentation, and new lines to make JSON readable for humans. Minification removes all unnecessary whitespace and new lines, reducing file size. Use formatted JSON during development and debugging, and minified JSON for production and API communication where data size matters.

The most common JSON errors are: trailing comma after the last element, single instead of double quotes for strings, comments (JSON does not support comments), unescaped special characters in strings, and missing quotes around object keys. Our tool shows the exact line and position of the error.

Absolutely safe. All JSON is parsed, formatted, and validated exclusively in your browser using the built-in JSON.parse() and JSON.stringify() functions. Nothing is sent to the server or stored. Your data never leaves your browser.

Our tool can handle JSON files up to several megabytes without issues. For extremely large files (100MB+), the browser may slow down because all processing happens locally. In that case, we recommend desktop tools such as VS Code or the jq command-line tool. For standard API responses and configuration files, our tool is more than enough.