JSON to JSDoc Converter
Convert JSON objects to JSDoc documentation comments with automatic type detection. Generates typedef, property, param, or type annotations for JavaScript code documentation. Perfect for API documentation, function parameters, and type definitions.
Conversion Options
Recommended Settings
JSDoc Best Practices
- •Use @typedef for reusable type definitions across your codebase
- •Mark optional parameters with [paramName] notation for clarity
- •Include descriptions in production code to help other developers
- •Use @param for documenting function parameters with their types
- •Leverage nested types for complex object structures
Type Detection Features
- •Automatically detects string, number, boolean, object, and array types
- •Recognizes ISO 8601 date strings and converts them to Date type
- •Handles nested objects by generating separate type definitions
- •Detects arrays of objects and creates appropriate array type annotations
- •Null values can be marked as optional fields with bracket notation
Pro Tips
- •Paste JSON and it auto-validates - conversion happens automatically when valid
- •Choose @typedef format for reusable type definitions in your codebase
- •Use @param format when documenting function signatures
- •All processing happens in your browser - your data never leaves your device
Most Popular
Most users generate @typedef definitions with optional field marking enabled
When to Use This Tool
Document API response structures with JSDoc type definitions. Convert JSON API responses to @typedef comments that describe the shape of data returned by endpoints. Helps developers understand API contracts and provides IDE autocomplete support for response objects.
Generate @param annotations for function documentation from example objects. Convert sample input objects to JSDoc parameter comments with proper type annotations. Essential for documenting functions that accept complex configuration objects or structured data.
Create type definitions for configuration objects used throughout your application. Convert example config objects to @typedef comments that document available options, their types, and whether they're optional. Improves code maintainability and IDE support.
Document data models and schemas with JSDoc type definitions. Convert database records, state objects, or data structures to @typedef comments that serve as single source of truth for data shapes. Particularly useful for projects not using TypeScript.
How It Works
Paste your JSON object into the input field on the left side
Choose an output format: @typedef, @property, @param, or @type
Customize the type name and enable optional formatting features
The tool parses JSON and detects types for each field automatically
Nested objects are converted to separate type definitions with proper references
Arrays are detected and annotated with appropriate array syntax (Type[])
Copy the JSDoc output to clipboard or download it as a .js file
All processing happens in your browser - your JSON data never leaves your device
100% Private
Files never leave your device. All processing happens locally in your browser.
Lightning Fast
Powered by Pure JavaScript for optimal performance on modern browsers.
Secure
No data collection, no tracking, no sign-up required.
Frequently Asked Questions
What is JSDoc?
JSDoc is a documentation standard for JavaScript that uses special comment blocks to describe types, parameters, and behavior. It provides type information without TypeScript, enables IDE autocomplete, and serves as inline documentation. JSDoc comments start with /** and include tags like @typedef, @param, and @property.
What's the difference between @typedef and @type?
@typedef creates a reusable named type definition that can be referenced throughout your codebase. @type annotates a specific variable or constant with its type. Use @typedef when you need to document a structure used in multiple places, and @type for one-off variable annotations.
How does this tool handle nested objects?
The tool automatically detects nested objects and generates separate @typedef definitions for them. Nested types are created with PascalCase names derived from their property names. The main type then references these nested types, creating a complete type hierarchy that mirrors your JSON structure.
Can I use JSDoc instead of TypeScript?
Yes! JSDoc provides type safety in plain JavaScript files. TypeScript's compiler can check JSDoc annotations with the --checkJs flag. You get many TypeScript benefits (type checking, IDE autocomplete) without converting to .ts files. However, TypeScript offers more advanced features and stricter enforcement.
What does marking null values as optional do?
When enabled, fields with null values are wrapped in brackets [fieldName] in the JSDoc output. This indicates the field is optional and might not be present. This is useful when your JSON represents a partial object or API response where some fields are conditionally included.
How are array types detected?
The tool examines the first element of arrays to determine the type. For primitive arrays like [1, 2, 3], it generates number[]. For object arrays, it creates a new type definition for the object structure and uses TypeName[] syntax. Empty arrays default to Array type.
When should I use @param format?
Use @param format when documenting function parameters. Convert an example argument object to @param tags that describe each property. This is perfect for functions accepting configuration objects, options parameters, or structured data. Each property becomes a separate @param annotation with its type.
Is my JSON data secure using this tool?
Yes, your data is completely private. All conversion happens entirely in your browser using JavaScript - nothing is sent to any server. Your JSON never leaves your device. However, remember that JSDoc comments are documentation, not security - they don't encrypt or protect your data.