What is JSON?
JSON (JavaScript Object Notation) is a text-based data format derived from JavaScript object syntax. It is widely used for transmitting data between a server and web application as an alternative to XML. JSON is language-independent and supported by virtually every programming language.
JSON Data Types
JSON supports the following data types:
- String: "Hello, World!"
- Number: 42 or 3.14
- Boolean: true or false
- Array: [1, 2, 3]
- Object: {"key": "value"}
- Null: null
Why Format JSON?
APIs often return minified JSON — a single line with no spaces or line breaks — to reduce payload size. While this is efficient for machines, it is unreadable for humans. Formatting (or "beautifying") JSON adds indentation and line breaks to reveal the structure clearly.
JSON Formatting Rules
Properly formatted JSON follows these conventions:
- Keys must be strings enclosed in double quotes
- Values are separated from keys by a colon (:)
- Key-value pairs are separated by commas
- No trailing commas after the last element
- Strings must use double quotes, not single quotes
How to Format JSON Online
The easiest way to format JSON is to use our free JSON Formatter tool. Simply paste your raw JSON, click Format, and instantly get a beautifully indented result with syntax highlighting.
Common JSON Errors and Fixes
Trailing commas: Remove the comma after the last item in an object or array.
Single quotes: Replace all single-quote strings with double quotes.
Unquoted keys: Ensure all object keys are wrapped in double quotes.
Conclusion
Understanding and properly formatting JSON is a fundamental skill for any developer or tech-savvy professional. Use our free JSON Formatter tool to validate and beautify your JSON data in seconds.