Developer
Browser-based
JSON Formatter
Format, minify, and validate JSON data. See clear error messages with line numbers.
JSON is processed entirely in your browser.
How to use JSON Formatter
Use JSON Formatter when you need a quick developer utility without installing software or creating an account. Enter your values or text in the tool above, review the instant result, then copy or save the output when the tool supports it.
- Works directly in a modern browser on desktop or mobile.
- Designed for fast repeat use from the root URL
/json-formatter. - Input stays in your browser unless a tool clearly says otherwise.
Features
- Format JSON with proper indentation
- Minify JSON to compact form
- Validate JSON and show errors
- Error messages with line numbers
- Copy formatted or minified output
Use Cases
- Reading minified API responses
- Debugging JSON configuration
- Preparing JSON for APIs
- Validating JSON data
Frequently Asked Questions
Is my JSON uploaded to a server?
No. All formatting, minification, and validation happens locally in your browser using JavaScript's native JSON parser.
What happens if my JSON has errors?
The tool will display a clear error message indicating the problem and, when possible, the line number where the error occurs.
Can I format already-formatted JSON?
Yes, you can also minify formatted JSON to reduce its size.
What's the difference between format and minify?
Format adds whitespace and indentation for readability. Minify removes all unnecessary whitespace to reduce file size.