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JSON Formatter & Validator

Format, validate, minify, and analyze JSON data with syntax highlighting, tree view, and real-time statistics. Free and privacy-focused.

Privacy Notice: All JSON processing happens in your browser. Your data never leaves your device.

Input JSON

Formatted Output

Formatted JSON will appear here

JSON Formatting Tips

  • Use proper indentation for better readability (2 or 4 spaces)
  • All keys must be enclosed in double quotes
  • String values must use double quotes, not single quotes
  • No trailing commas after the last element in arrays or objects
  • Use minification to reduce file size for production APIs
  • Sort keys alphabetically for consistent diffs and version control

Key Features

Smart Formatting

Automatically format JSON with customizable indentation (2 spaces, 4 spaces, or tabs). Choose between beautified or minified output.

🔍

Real-Time Validation

Instant validation as you type with detailed error messages showing exact line and column numbers for syntax errors.

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Tree View Explorer

Navigate complex JSON structures with an interactive tree view. Expand and collapse nodes to explore nested data.

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Syntax Highlighting

Color-coded syntax highlighting makes it easy to distinguish between keys, strings, numbers, booleans, and null values.

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Statistics & Metrics

View detailed statistics including object count, array count, key count, maximum depth, and file size.

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100% Private

All processing happens in your browser. Your JSON data never leaves your device - no server uploads or logging.

Understanding JSON Format

JSON (JavaScript Object Notation) is the most widely used data interchange format on the web. It is lightweight, human-readable, and easy for machines to parse.

Data Types

  • String:Text enclosed in double quotes - "hello"
  • Number:Integer or decimal - 42, 3.14
  • Boolean:true or false
  • Null:null - represents no value
  • Array:Ordered list - [1, 2, 3]
  • Object:Key-value pairs - {"key": "value"}

JSON Rules

  • Keys must be strings in double quotes
  • String values use double quotes only
  • Commas separate elements in arrays/objects
  • No trailing commas after last element
  • No comments allowed in JSON
  • No single quotes for strings
  • No unquoted keys in objects

Example: Valid JSON

{
  "name": "John Doe",
  "age": 30,
  "email": "[email protected]",
  "isActive": true,
  "address": {
    "street": "123 Main St",
    "city": "San Francisco",
    "state": "CA"
  },
  "hobbies": ["reading", "hiking", "photography"],
  "metadata": null
}

Common JSON Errors

❌ Invalid JSON

Missing Comma

{
  "name": "John"
  "age": 30  ← Missing comma
}

Trailing Comma

{
  "name": "John",
  "age": 30,  ← Trailing comma
}

Single Quotes

{
  'name': 'John'  ← Must use double quotes
}

✓ Valid JSON

Proper Commas

{
  "name": "John",
  "age": 30
}

No Trailing Comma

{
  "name": "John",
  "age": 30
}

Double Quotes

{
  "name": "John"
}

Common Use Cases

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API Debugging

Format API responses to identify issues, validate structure, and understand nested data relationships.

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Configuration Files

Validate and format JSON configuration files for applications, ensuring proper syntax before deployment.

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Data Analysis

Explore complex data structures with tree view, calculate statistics, and understand data hierarchy.

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Code Reviews

Sort keys alphabetically for consistent formatting and easier diff comparison in version control.

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Minification

Reduce JSON file size by removing whitespace for production APIs and optimized data transfer.

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Documentation

Format JSON examples for technical documentation, tutorials, and API guides with proper indentation.

Frequently Asked Questions

Find answers to common questions

Yes, absolutely! All JSON formatting and validation happens entirely in your browser using JavaScript. Your data is never sent to our servers, stored, or logged anywhere. The tool runs completely client-side for maximum privacy and security.

Need Help with API Development?

Our development team can help you design, build, and optimize APIs with proper JSON schema validation, documentation, and best practices.