Free JSON Formatter & Validator

Format, validate, and beautify JSON data instantly. Perfect for developers, API testing, and debugging with syntax highlighting and error detection.

JSON Formatter & Validator Tool

Paste any JSON data to format, validate, or minify

Quick Examples

👤 Simple Object

{"name":"John","age":30,"city":"New York"}

Click to format this minified JSON

📦 Array of Objects

[{"id":1,"name":"Product A"...}]

Format an array of product objects

🏗️ Nested Structure

{"user":{"profile":{"name":"Jane"...}}}

Complex nested JSON object

❌ Invalid JSON

{"name":"Test","invalid":}

Test error detection with invalid syntax

Understanding JSON

JSON (JavaScript Object Notation) is a lightweight, text-based data interchange format that's easy for humans to read and write. Despite its name, JSON is language-independent and is used across virtually all modern programming languages.

JSON Data Types

📝 String

"Hello World"

Text wrapped in double quotes

🔢 Number

42, 3.14, -10

Integer or floating-point

✅ Boolean

true, false

Logical true or false values

⭕ Null

null

Represents empty or no value

🏗️ Object

{"key": "value"}

Collection of key-value pairs

📋 Array

[1, 2, 3]

Ordered list of values

Common JSON Use Cases

  • **REST API** data exchange between servers and clients
  • **Configuration files** for applications and services
  • **Data storage** in NoSQL databases like MongoDB
  • **Web development** for AJAX requests and responses
  • **Mobile apps** for data synchronization
  • **Microservices** communication and message queues

JSON Syntax Rules

Strings Must Use Double Quotes

✅ "valid" ❌ 'invalid' ❌ `invalid`

No Trailing Commas

✅ {"a": 1, "b": 2} ❌ {"a": 1, "b": 2,}

No Comments Allowed

JSON doesn't support // or /* */ comments

Case Sensitive

true ≠ True ≠ TRUE

Why Format JSON?

🔍 Readability

Proper indentation makes complex data structures easy to understand

🐛 Debugging

Formatted JSON helps identify syntax errors and structural issues

📊 Analysis

Better visualization of data relationships and hierarchy

🤝 Collaboration

Easier to review and share formatted JSON with team members

Best Practices

  • Always validate JSON before using it in production
  • Use meaningful key names that describe the data
  • Keep nesting levels reasonable (typically under 5 levels)
  • Consider using schemas for validation in larger projects
  • Minify JSON for production to reduce bandwidth
  • Use arrays for ordered data, objects for unordered key-value pairs

Frequently Asked Questions

What's the difference between formatting and minifying JSON?

Formatting adds whitespace and indentation for readability, while minifying removes all unnecessary whitespace to reduce file size for production use.

Can I use single quotes in JSON?

No, JSON specification requires double quotes for strings. Single quotes will cause a syntax error. Use our validator to catch these issues.

Is this tool secure for sensitive data?

Yes, all JSON processing happens in your browser - no data is sent to our servers. However, avoid processing highly sensitive data in any online tool.

How large JSON files can I format?

The tool can handle reasonably large JSON files (up to several MB), but very large files may impact browser performance. For huge files, consider using command-line tools.