JSON Formatter & Validator
Format, validate, and beautify JSON data instantly. Minify or prettify JSON with customizable indentation and syntax highlighting.
Quick Examples
What is JSON?
JSON (JavaScript Object Notation) is a lightweight, text-based data format that's easy for humans to read and write, and easy for machines to parse and generate. It's the most popular format for data exchange between web applications and APIs.
JSON is built on two fundamental structures:
- Objects: Unordered collections of key-value pairs enclosed in curly braces
{} - Arrays: Ordered lists of values enclosed in square brackets
[]
JSON supports various data types including strings, numbers, booleans, null, objects, and arrays, making it versatile for representing complex data structures.
How JSON Formatter Works
Our JSON formatter provides several powerful features to help you work with JSON data:
- Validation: Checks if your JSON is syntactically correct and identifies errors
- Formatting/Beautifying: Adds proper indentation and line breaks for readability
- Minification: Removes all whitespace to create the smallest possible representation
- Syntax Checking: Identifies missing brackets, commas, quotes, and other syntax issues
- Key Sorting: Optionally sorts object keys alphabetically for consistency
- Statistics: Shows character count, line count, and data type information
The tool runs entirely in your browser, ensuring your data remains private and processing is instant.
Common JSON Errors & Solutions
Missing Quotes Around Keys
❌ Wrong: {name: "John"}
✅ Correct: {"name": "John"}
All keys must be enclosed in double quotes.
Trailing Commas
❌ Wrong: {"name": "John", "age": 30,}
✅ Correct: {"name": "John", "age": 30}
JSON doesn't allow commas after the last item.
Single Quotes
❌ Wrong: {'name': 'John'}
✅ Correct: {"name": "John"}
Only double quotes are valid in JSON.
Unescaped Special Characters
❌ Wrong: {"text": "Line 1 Line 2"}
✅ Correct: {"text": "Line 1\\nLine 2"}
Special characters must be escaped with backslash.
Common Use Cases
- API Development: Format API responses for easier reading and debugging
- Configuration Files: Beautify config files for better maintainability
- Data Validation: Verify JSON data before sending to APIs or databases
- Code Review: Format JSON for easier review and comparison
- Learning: Understand JSON structure by seeing properly formatted examples
- Debugging: Identify syntax errors in JSON strings quickly
- Data Migration: Clean up and validate JSON data before migration
- Performance Optimization: Minify JSON to reduce payload size
FAQ
JSON Best Practices
- Use Descriptive Keys: Choose clear, meaningful key names (e.g., "firstName" not "fn")
- Be Consistent: Use the same naming convention throughout (camelCase, snake_case, etc.)
- Keep It Flat: Avoid excessive nesting; 3-4 levels deep maximum for readability
- Validate Early: Check JSON validity before sending to production
- Document Structure: Use JSON Schema to document expected format
- Handle Nulls Carefully: Be explicit about null vs. missing properties
- Use Arrays Consistently: Even single items should be in arrays if the field can have multiple values
- Minify in Production: Format for development, minify for production
Security & Privacy
- Client-Side Processing: All formatting happens in your browser
- No Data Transmission: Your JSON never leaves your device
- No Storage: Nothing is saved or logged
- Safe to Use: Perfect for sensitive API responses or configuration data
Note: While this tool is safe, always be cautious when pasting sensitive data into any web application. Never include passwords, API keys, or personal information in shared examples.
Usage Tips
- Click "Format JSON" to automatically validate and beautify your JSON
- Enable "Sort keys" for easier comparison between JSON objects
- Minify JSON before sending over network to reduce bandwidth
- Use formatted JSON in documentation and code examples
- Check the statistics panel to see object/array type and size
- Copy formatted JSON directly to your IDE or API client
- Use keyboard shortcuts: Ctrl+A to select all, Ctrl+C to copy
- Bookmark this tool for quick access during development