JSON Formatter
Format, validate, and minify JSON data. Beautify messy JSON with customizable indentation.
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What is JSON?
JSON (JavaScript Object Notation) is a lightweight data format that's become the universal language of web APIs and configuration files.
Think of JSON as a structured way to write data that both humans and computers can easily read:
{
"name": "John",
"age": 30,
"hobbies": ["reading", "coding"]
}
JSON Syntax Rules
Data Types:
- Strings:
"hello"(always double quotes!) - Numbers:
42,3.14,-17 - Booleans:
true,false - Null:
null - Arrays:
[1, 2, 3] - Objects:
{"key": "value"}
Common Mistakes:
| Wrong ❌ | Correct ✅ |
|---|---|
'hello' | "hello" |
{name: "John"} | {"name": "John"} |
[1, 2, 3,] | [1, 2, 3] |
JSON doesn't allow trailing commas, comments, or single quotes. These are the most common syntax errors!
Why Format JSON?
Readability: Minified JSON is hard to read:
{"users":[{"name":"John","age":30},{"name":"Jane","age":25}]}
Formatted version is much clearer:
{
"users": [
{"name": "John", "age": 30},
{"name": "Jane", "age": 25}
]
}
When to Minify
Minification removes all unnecessary whitespace, reducing file size. Use it for:
- API responses (faster transmission)
- Configuration files in production
- Storing JSON in databases
A 100KB formatted JSON might become 60KB when minified!
JSON Best Practices
1. Use Consistent Naming
- camelCase:
firstName - snake_case:
first_namePick one and stick with it!
2. Avoid Deep Nesting More than 3-4 levels deep becomes hard to maintain.
3. Validate Before Using Always validate JSON from external sources.
4. Use Arrays for Lists Even single items should be arrays if they might have multiple values later.