What is JSON to ArkTS Type Generator?
This tool converts JSON data into ArkTS (HarmonyOS) interface or class definitions with proper type inference. It generates type-safe ArkTS code compatible with HarmonyOS development, supporting optional fields, nested interfaces, and reactive decorators.
How to Use
- Select output style (interface or class)
- Configure HarmonyOS-specific options
- Paste your JSON data and click "Generate"
- Copy the ArkTS types into your HarmonyOS project
Why Use This Tool?
Tips & Best Practices
- ArkTS restricts the use of any type
- Use @ObservedV2 for state-driven UI updates
- Optional fields (?:) for nullable JSON values
- ArkTS interfaces are similar to TypeScript but stricter
Frequently Asked Questions
How are JSON types mapped to ArkTS?
JSON strings → string, integers → number, floats → number, booleans → boolean, null → T | null (or T? with optional fields), arrays → T[], objects → separate interfaces. ArkTS does not support the any type — null values use Object as fallback or optional fields.
What is @ObservedV2 in ArkTS?
@ObservedV2 is a decorator in ArkTS used for state management in HarmonyOS. When applied to a class, it enables reactive state tracking so the UI automatically updates when properties change. Properties decorated with @Trace trigger re-renders when modified.
What is the difference between interface and class output?
Interface output generates export interface definitions with type annotations only — lightweight and ideal for type checking. Class output generates export class definitions with typed properties, a constructor, and optional @ObservedV2/@Trace decorators for reactive state management in HarmonyOS UI components.
Why does ArkTS not allow the any type?
ArkTS is a statically-typed subset of TypeScript designed for performance and safety in HarmonyOS. It prohibits the any type to ensure type safety at compile time, reducing runtime errors. Use Object or unknown instead when the type is truly unknown.
Is my data sent to a server?
No, all processing happens entirely in your browser. Your JSON data never leaves your device.