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About this tool
Paste any JSON and hit Format to pretty-print it with configurable indentation and full syntax highlighting. Minify strips all whitespace for compact transmission. Validate reports the exact line and column of any syntax error. Everything runs locally in your browser — your data never leaves your machine.
JSON (JavaScript Object Notation) is a lightweight text format for storing and exchanging structured data. It uses key-value pairs, arrays, strings, numbers, booleans, and null. JSON is language-independent and is the dominant format for REST APIs, configuration files, and data interchange on the web.
Raw JSON is often returned by APIs as a single unbroken line with no whitespace — valid, but unreadable. Formatting (also called "pretty-printing") adds consistent indentation and line breaks so the structure is immediately legible. The JSON content itself is unchanged; only the presentation differs.
Minifying removes all unnecessary whitespace, newlines, and indentation, producing the most compact valid representation. This reduces file size and is useful when transmitting JSON over a network or embedding it in code where readability is less important than efficiency.
The browser's native JSON.parse() is used for validation. When parsing fails, the error message includes the position of the first invalid character. Common causes: trailing commas (not allowed in JSON), single-quoted strings (JSON requires double quotes), unescaped special characters, and missing closing brackets or braces.
No. All processing — parsing, formatting, minifying, and syntax highlighting — is performed by JavaScript running inside your browser tab. No data is transmitted anywhere. Closing the tab permanently discards the content.
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