10 JSON Formatting Tips Every Developer Should Know

JSON (JavaScript Object Notation) has become the universal language for data exchange in web development. Whether you're building APIs, configuring applications, or storing data, properly formatted JSON is crucial for maintainability and debugging. Here are 10 essential tips that will transform how you work with JSON.

1. Always Use Consistent Indentation

Consistent indentation is the foundation of readable JSON. Choose either 2 or 4 spaces and stick with it throughout your project. Most developers prefer 2 spaces for JSON to keep it compact.

// Good: Consistent 2-space indentation { "user": { "id": 123, "name": "John Doe", "preferences": { "theme": "dark", "notifications": true } } } // Bad: Inconsistent indentation { "user": { "id": 123, "name": "John Doe", "preferences": { "theme": "dark", "notifications": true } } }

Pro Tip: Use our JSON Formatter to automatically fix indentation issues and beautify your JSON instantly.

2. Use Meaningful Property Names

Property names should be descriptive and follow a consistent naming convention. Choose between camelCase, snake_case, or kebab-case and use it consistently across your entire project.

// Good: Descriptive camelCase names { "firstName": "John", "lastName": "Doe", "emailAddress": "[email protected]", "phoneNumbers": [ { "type": "mobile", "number": "+1-555-0123" } ] } // Bad: Vague or inconsistent names { "fn": "John", "last_name": "Doe", "email-addr": "[email protected]", "phones": [ { "t": "mobile", "num": "+1-555-0123" } ] }

3. Validate Your JSON Regularly

Invalid JSON will break your applications. Common syntax errors include trailing commas, unquoted keys, and single quotes instead of double quotes. Always validate before deploying.

// Invalid JSON (trailing comma) { "name": "John", "age": 30, } // Valid JSON { "name": "John", "age": 30 }

Use validation tools during development to catch errors early. Our JSON Validator can help you identify and fix syntax errors instantly.

4. Choose Appropriate Data Types

JSON supports several data types: strings, numbers, booleans, arrays, objects, and null. Use the correct type for each value to ensure proper parsing and type safety.

// Good: Correct data types { "id": 123, // Number "active": true, // Boolean "name": "John Doe", // String "tags": ["developer", "js"], // Array "profile": { // Object "bio": "Full-stack developer" }, "avatar": null // Null for missing values } // Bad: Everything as strings { "id": "123", "active": "true", "name": "John Doe", "tags": "developer,js", "profile": "Full-stack developer", "avatar": "" }

5. Avoid Deep Nesting

While JSON allows unlimited nesting, deeply nested structures are hard to read and maintain. Try to keep nesting to 3-4 levels maximum. Consider flattening or restructuring when possible.

// Too deeply nested { "user": { "account": { "settings": { "preferences": { "notifications": { "email": { "frequency": "daily" } } } } } } } // Better: Flattened structure { "user": { "id": 123, "name": "John Doe" }, "accountSettings": { "emailNotifications": "daily", "theme": "dark" } }

6. Use Arrays for Ordered Data

When data has a natural order or when you need to maintain sequence, use arrays. For lookup tables or when order doesn't matter, use objects.

// Good: Array for ordered steps { "recipe": { "name": "Chocolate Cake", "steps": [ "Preheat oven to 350°F", "Mix dry ingredients", "Add wet ingredients", "Bake for 30 minutes" ], "ingredients": { "flour": "2 cups", "sugar": "1 cup", "cocoa": "0.5 cups" } } }

7. Handle Special Characters Properly

JSON requires proper escaping of special characters. Use double quotes for strings and escape characters like backslashes, quotes, and control characters correctly.

// Correct escaping { "message": "She said, \"Hello, world!\"", "path": "C:\\Users\\John\\Documents", "newline": "First line\nSecond line", "tab": "Column1\tColumn2" }

8. Consider Compression for Large Files

Large JSON files can impact performance. Remove unnecessary whitespace for production, but keep formatted versions for development. Consider using compression techniques.

// Development: Human-readable { "users": [ { "id": 1, "name": "John Doe", "email": "[email protected]" }, { "id": 2, "name": "Jane Smith", "email": "[email protected]" } ] } // Production: Minified {"users":[{"id":1,"name":"John Doe","email":"[email protected]"},{"id":2,"name":"Jane Smith","email":"[email protected]"}]}

9. Add Schema Validation

Use JSON Schema to define the structure and validation rules for your JSON data. This helps catch errors early and documents your data structure.

{ "$schema": "http://json-schema.org/draft-07/schema#", "type": "object", "properties": { "name": { "type": "string", "minLength": 1 }, "age": { "type": "integer", "minimum": 0, "maximum": 150 }, "email": { "type": "string", "format": "email" } }, "required": ["name", "email"] }

10. Use Comments Wisely (When Possible)

Standard JSON doesn't support comments, but some parsers allow them. For configuration files, consider using JSON5 or JSONC formats that support comments, or add a _comment field.

// Using a comment field { "_comment": "User configuration for the application", "user": { "_comment": "Default user settings", "theme": "dark", "autoSave": true } } // Or in JSON5 format (if supported) { // User configuration for the application user: { theme: "dark", // Dark theme is default autoSave: true // Auto-save every 5 minutes } }

Essential Tools for JSON Formatting

To implement these best practices effectively, you'll need the right tools. Here are some essential utilities:

JSON Formatter - Beautify and validate JSON instantly
Base64 Encoder - Encode JSON for safe transmission
UUID Generator - Generate unique identifiers for JSON objects
Regex Tester - Test patterns for JSON validation

Common JSON Formatting Mistakes to Avoid

Even experienced developers make these common mistakes:

Trailing commas: JSON doesn't allow trailing commas after the last element
Single quotes: Always use double quotes for strings and property names
Undefined values: Use null instead of undefined
Circular references: Avoid objects that reference themselves
Mixed data types in arrays: Be consistent with array element types when possible

Conclusion

Mastering JSON formatting is essential for modern web development. By following these 10 tips, you'll write more maintainable code, reduce debugging time, and improve collaboration with your team. Remember to validate your JSON regularly, use appropriate data types, and keep your structure as simple as possible.

Whether you're building REST APIs, configuring applications, or processing data, these formatting guidelines will serve you well. Start implementing them today, and use our free developer tools to streamline your JSON workflow.