JSON Formatter

Format and validate JSON with pretty-printing. Paste minified or messy JSON and get readable, indented output. Invalid JSON will be reported.

About this tool

JSON (JavaScript Object Notation) is a common format for storing and exchanging data. Minified JSON has no line breaks or spaces, which saves size but is hard to read. This tool adds indentation and line breaks so you can inspect and edit JSON easily. It also validates your input and reports syntax errors.

How to use

Paste your JSON string into the input box (e.g. from an API response or config file).
Click Format to pretty-print the JSON with indentation.
If the input is invalid, the tool will show an error message.
Copy the formatted result for use in your project or documentation.

Formatted JSON will appear here...

When to use this tool

Reading minified API responses or config files.
Preparing JSON for documentation or code reviews.
Debugging malformed JSON by seeing structure clearly.
Converting one-line JSON logs into readable form.

Tips

Valid JSON requires double quotes for keys and strings; single quotes are not allowed.
Trailing commas in arrays or objects make JSON invalid—remove them before formatting.

FAQ

Why does it say Invalid JSON?: Usually due to trailing commas, single quotes instead of double, or unescaped characters in strings. Check the error and fix the syntax.
Is my JSON sent to your server?: No. Formatting runs in your browser; your data never leaves your device.