JSON Tools
JSON Formatter
Beautify JSON and validate syntax with readable indentation and precise parse errors.
Processed locally — your data never leaves this browser.
Example input and output
Compact object
{"name":"Lumarc","tools":2}{
"name": "Lumarc",
"tools": 2
}How to use JSON Formatter
Paste or enter your json text, adjust any options, then run the tool. The result appears in the output panel where you can copy or download it.
What this tool does
The JSON Formatter turns compact or messy JSON into a readable structure while validating that the input is valid JSON. It is useful for API responses, configuration files and debugging payloads. It is free to use and designed for technical workflows where pasted data should stay private.
Common use cases
- Inspect API responses
- Review configuration files
- Prepare JSON for documentation
Privacy and security
Processed locally — your data never leaves this browser. Lumarc DevTools does not include a backend, account system or hidden analytics in this initial release.
Limitations
- JSON with comments or trailing commas is rejected because it is not valid JSON.
Frequently asked questions
Does this JSON formatter upload my data?
No. Formatting runs locally in your browser.
Can it fix invalid JSON automatically?
It reports syntax errors, but it does not guess or rewrite invalid data.