JSON Formatter & Validator Online
Paste messy JSON and get clean, indented, syntax-highlighted output in a click. Spot errors instantly, minify for production, or validate structure — all in your browser.
Format JSON NowNo software required · Works in any browser
Prettify & Indent
Turn a single-line JSON blob into neatly indented, readable output. Choose 2-space or 4-space indentation to match your project style.
Instant Validation
The tool highlights syntax errors with line and column numbers so you can find and fix problems in seconds.
Minify for Production
Strip whitespace and newlines to get the smallest possible JSON string, ready for API payloads or config files.
Syntax Highlighting
Keys, strings, numbers, booleans, and nulls are color-coded for easy scanning — even in deeply nested structures.
How It Works
Paste Your JSON
Paste a JSON string from an API response, config file, or clipboard. The tool accepts any valid (or invalid) JSON text.
Format or Validate
Click Prettify to indent, Minify to compress, or Validate to check for errors. Results appear instantly.
Copy the Output
Click the copy button to grab the formatted JSON. Paste it into your editor, terminal, or documentation.
Common Use Cases
API Response Debugging
Paste a raw API response to see the structure clearly. Identify missing fields, wrong types, or unexpected nesting at a glance.
Config File Editing
Format package.json, tsconfig, or CI configs before committing. Consistent indentation makes diffs cleaner in code review.
Minifying Payloads
Remove unnecessary whitespace from JSON before embedding it in URLs, environment variables, or database fields.
Learning & Documentation
Pretty-print example JSON for tutorials, README files, or Notion docs so readers can follow the data structure easily.
Superconverter vs Others
| Feature | Superconverter | Others |
|---|---|---|
| Data sent to server | No | Yes |
| Syntax highlighting | Full color-coding | Basic or none |
| Error location | Line and column | Generic message |
| Minify mode | One click | Separate tool |
| Ads and tracking | None | Heavy |
Frequently Asked Questions
Can I format invalid JSON?
The tool will try to parse it and show you exactly where the syntax error is — line number, column, and a description of what went wrong — so you can fix it.
Does formatting change the data?
No. Prettifying only adds whitespace and line breaks. Minifying only removes them. The actual data values are never modified.
Is there a size limit?
There is no hard limit. The tool handles JSON files of several megabytes. Extremely large files (50 MB+) may slow down depending on your device.
Can I use tabs instead of spaces?
The default is spaces (2 or 4). If you need tabs, you can copy the output and do a find-and-replace in your editor.
Is my JSON data private?
Yes. Everything runs locally in your browser. No data is sent to any server, making it safe for API keys, tokens, and sensitive payloads.
Clean Up Your JSON in Seconds
Free, private, and distraction-free. Paste, format, copy — done.
Open JSON Formatter