Web Tools
JSON to TypeScript
Convert JSON data to TypeScript interfaces or type aliases. Infer nested types, arrays, optional properties, and more. Runs entirely in your browser — your data never leaves your machine.
json typescript converter types code-generator
Published May 28, 2026
All interactive tools run entirely in your browser. Your data never leaves your device.
How It Works
Paste any JSON data and instantly get TypeScript interfaces or type aliases. The tool infers types from values, handles nested objects, arrays, null, and mixed types. Configure the root type name, choose between interface and type, toggle optional properties and exports.
Features
- Interface or type alias: choose your preferred TypeScript style
- Nested type inference: objects within objects generate separate named types
- Array handling: homogeneous arrays get typed elements, mixed arrays use union types
- Configurable root name: name your top-level type
- Optional properties: toggle
?on all properties - Export toggle: add or remove
exportkeyword - 5 example payloads: simple, nested, array, API response, mixed types
- Private: runs entirely in the browser — no data transmitted
Use Cases
- Quickly generating types for API response data
- Bootstrapping TypeScript interfaces from JSON fixtures
- Converting JSON config files to typed configurations
- Learning how JSON structures map to TypeScript types