JSON Formatter & Validator
Format, validate, and minify JSON instantly in your browser. Syntax error detection with descriptive messages. No data sent to servers.
✓ Free✓ Client-Side✓ No Registration✓ Instant Results
Input JSON
0 chars
Output
JSON Syntax Quick Reference
Valid JSON Data Types
string: "hello world"
number: 42 or 3.14
boolean: true or false
null: null
array: [1, 2, 3]
object: {"key": "value"}
Common JSON Errors
- ✗ Trailing comma after last item
- ✗ Single quotes instead of double quotes
- ✗ Unquoted property names
- ✗ Comments (JSON does not support comments)
- ✗ Missing comma between items
- ✗ Unescaped special characters in strings
- ✗ Mismatched brackets or braces
Frequently Asked Questions
Is my JSON data safe when using this tool?
Yes. This JSON formatter runs entirely in your browser using JavaScript. Your JSON data is never sent to any server. All processing happens locally on your device.
What is JSON formatting?
JSON formatting (also called JSON beautifying or pretty-printing) adds indentation and line breaks to make JSON data human-readable. Minified JSON removes whitespace to reduce file size.
What is JSON validation?
JSON validation checks if your JSON follows correct syntax rules (RFC 8259). Common errors include missing quotes, trailing commas, unescaped special characters, and mismatched brackets. Our validator pinpoints the exact error.
Can I format JSON with tabs instead of spaces?
Currently our tool supports 2-space and 4-space indentation, which are the most common standards. Tab indentation can be added by pasting formatted output into your code editor.