Free tools
JSON Formatter
Format and prettify minified JSON instantly in your browser — free online JSON beautifier with syntax validation.
Formatted JSON
JSON Formatter & Prettifier Online
Paste any JSON — minified or messy — into the field above and click Format / Prettify to get nicely indented output. Use Minify to strip all whitespace for compact output. If the JSON is invalid, an error message will tell you exactly what went wrong.
What Is JSON Formatting?
JSON formatting (or prettifying) adds consistent indentation and line breaks to a compact JSON string, making it easy to read and navigate. Minifying does the reverse — it removes all unnecessary whitespace to reduce file size.
Common Uses
- Reading API responses that are returned as a single line
- Validating that a JSON string is well-formed before using it
- Minifying JSON config files to reduce payload size
- Debugging JSON embedded in logs or environment variables
Frequently Asked Questions
How do I format JSON?
Paste your minified or unformatted JSON into the input field. The tool automatically parses and reformats it with proper indentation and line breaks. If the JSON is invalid, you'll see an error message with details about what's wrong.
What is pretty-printing?
Pretty-printing (or beautification) transforms compact JSON into a human-readable format with proper indentation, line breaks, and spacing. This makes it easier to read, debug, and understand complex JSON structures.
Can I minify JSON with this tool?
Yes. The tool works both ways — you can prettify minified JSON or minify pretty JSON. Toggle between 'Beautify' and 'Minify' modes. Minification removes all unnecessary whitespace to create the most compact valid JSON.
Does this tool validate JSON?
Yes. The tool validates your JSON syntax as it processes it. If your JSON has errors (missing commas, unmatched brackets, invalid values), you'll get a clear error message indicating what and where the problem is.
Why is my JSON invalid?
Common JSON errors include: trailing commas after the last item in an array or object, using single quotes instead of double quotes for strings, comments (which aren't allowed in strict JSON), unquoted keys, and unescaped special characters in strings.
Is this tool secure?
Yes. All formatting happens entirely in your browser. Your JSON data is never sent to any server. For sensitive data like API responses or configuration files, this local processing ensures your information stays private.