JSON Formatter
JSON formatter online to format, prettify, and validate JSON. Instantly beautify JSON, detect syntax errors, and fix invalid JSON directly in your browser.
Input
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Output
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Features
- Instant JSON formatting with syntax validation
- Customizable indentation (2, 4, or 8 spaces)
- One-click minification for production
- Real-time error detection with line numbers
- Copy formatted output instantly
- Swap input/output for easy re-formatting
Common Use Cases
- Format minified API responses for debugging
- Beautify compressed JSON config files
- Prepare JSON for code reviews
- Validate JSON syntax before deployment
- Reduce file size with minification
Understanding JSON Formatting
JSON (JavaScript Object Notation) is a lightweight data format that's human-readable and machine-parseable. JSON formatting adds whitespace and indentation to make the structure visible.
Why format JSON?
- Debugging - See the structure of API responses clearly
- Readability - Understand nested objects and arrays
- Validation - Spot syntax errors like missing commas or brackets
- Development - Work with configuration files more easily
Minified vs Formatted: Minified JSON removes whitespace for smaller file size (production), while formatted JSON adds indentation for readability (development).
Examples
{
"name": "John Doe",
"age": 30,
"active": true
}{
"name": "John"
"age": 30
}{
"items": [1, 2, 3,]
}{'name': 'John'}Frequently Asked Questions
Formatting adds indentation for readability, while validation checks syntax correctness. Our tool does both simultaneously.
Use 2 spaces for JavaScript/TypeScript projects and 4 spaces for Python/Java. Consistency within your project matters most.
No, minified and formatted JSON are functionally identical. Minifying only removes whitespace to reduce file size.
Standard JSON does not support comments. Some parsers accept JSONC (JSON with Comments), but it's not part of the official spec.
Common causes: missing commas, trailing commas, single quotes instead of double quotes, or unescaped special characters. Check the line number in the error message.
Yes! Everything runs in your browser - no data is sent to servers. Completely safe for sensitive information.
Check for syntax issues at the error line: missing commas, extra commas, incorrect quotes, or NaN/undefined values.
Yes, though very large files (10MB+) may take a moment. For huge files, consider a desktop JSON editor.