JSON Formatter
Format, validate, and minify your JSON data instantly
Input JSON
Formatted Output
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data interchange format that’s easy for humans to read and write, and easy for machines to parse and generate. It’s widely used for APIs, configuration files, and data storage.
Objects
Key-value pairs enclosed in curly braces. Keys must be strings in double quotes.
Arrays
Ordered lists of values enclosed in square brackets, separated by commas.
Strings
Text values must be enclosed in double quotes. Single quotes are not valid.
Numbers
Integer or floating-point numbers. No quotes needed. Supports scientific notation.
JSON Data Types
| Type | Example | Description |
|---|---|---|
| String | "Hello World" | Text in double quotes |
| Number | 42, 3.14 | Integer or float, no quotes |
| Boolean | true, false | Lowercase only |
| Null | null | Empty/no value, lowercase |
| Object | {"key": "value"} | Unordered key-value pairs |
| Array | [1, 2, 3] | Ordered list of values |
JSON Best Practices
- Use double quotes for strings
- Use camelCase for key names
- Keep structure consistent
- Validate before sending to APIs
- Use meaningful key names
- Use single quotes for strings
- Add trailing commas
- Include comments (not valid)
- Use undefined as a value
- Forget to escape special characters
Frequently Asked Questions
JSON is a text format for data exchange, while JavaScript objects are in-memory data structures. JSON requires double quotes for keys and strings, doesn’t support functions or undefined, and is always a string when transmitted.
JSON was designed to be a minimal data format. Comments were intentionally excluded to keep parsing simple. If you need comments, consider using JSON5 or YAML.
Use backslash to escape: \” for quotes, \\ for backslash, \n for newline, \t for tab. Unicode can be escaped as \uXXXX.
Yes, minifying removes whitespace and reduces payload size, improving transfer speed. Most APIs return minified JSON by default.
The official MIME type is application/json. Use this in Content-Type headers when sending JSON and Accept headers when requesting JSON.