Type Generator
JSON to TypeScript online. Generate TypeScript interfaces or Go structs from JSON instantly. Convert JSON to types directly in your browser.
JSON Input
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Generated TypeScript
TypeScript Output Features:
- • Generates interfaces with proper property types
- • Handles nested objects by creating separate interfaces
- • Arrays are typed based on first element
- • Quotes keys that aren't valid identifiers
Features
- Generate TypeScript interfaces from JSON
- Generate Go structs from JSON
- Handles nested objects and arrays
- Optional fields detection
- Copy generated code instantly
- Supports complex types
Common Use Cases
- Create TypeScript types from API responses
- Generate Go structs for JSON unmarshaling
- Speed up type-safe development
- Document API data structures
- Ensure type safety in projects
Understanding Type Generation
Type generation automatically creates type definitions (TypeScript interfaces or Go structs) from JSON examples.
How it works:
- Inference - Analyzes JSON structure to determine types
- Nested types - Creates separate interfaces for nested objects
- Arrays - Detects array element types
- Naming - Generates meaningful type names from keys
Type safety: Having proper types helps catch bugs at compile-time, enables autocomplete in IDEs, and makes code more maintainable.
Examples
Input: {"name": "Alice", "age": 30}
Output:
interface Root {
name: string;
age: number;
}Input: {"user": {"name": "Alice"}}
Output:
interface User {
name: string;
}
interface Root {
user: User;
}Frequently Asked Questions
The tool generates types based on the provided JSON. For optional fields, you may need to manually add ? in TypeScript.
It will generate a union type (TypeScript) or use interface{} (Go) for mixed-type arrays.
Generated names are based on property keys. You can copy the output and rename types as needed in your code.
Yes! Null values are typed as null in TypeScript or *Type (pointer) in Go.
The generator recursively creates types for all nested levels, creating intuitive type hierarchies.