JSON to TypeScript Interface Generator

Generate TypeScript interfaces or type aliases from JSON (local, no uploads)

Convert raw JSON into clean TypeScript interfaces or type aliases instantly. This JSON to TypeScript generator runs entirely in your browser — your data never leaves your device. Perfect for frontend developers, API consumers, and TypeScript projects.
Paste any JSON payload, generate strongly typed TypeScript definitions, and copy or download the results immediately. Supports nested objects, arrays, union types, and ISO date detection.
Paste JSON on the left. Click Generate. Copy/Download TypeScript on the right.
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TypeScript Output

About this tool

Convert raw JSON into clean TypeScript interfaces or type aliases instantly. This free online JSON to TypeScript generator runs entirely in your browser — no uploads and no server-side processing. It’s built for frontend developers and API consumers who want fast, accurate typings for real-world responses, configs, and payloads.

Common use cases

  • Generate TypeScript interfaces from API responses
  • Create typed models for React, Angular, or Node projects
  • Turn backend JSON payloads into frontend-safe type definitions
  • Sanity-check object shape before implementation
  • Speed up schema modeling during prototyping

How it works

The generator parses valid JSON and infers TypeScript types from values: primitives map to string/number/boolean, nested objects become nested interfaces/types, and arrays are typed based on detected structure. Because it runs locally in your browser, your JSON never leaves your device.

FAQ

Does this send JSON to a server?

No — parsing and type generation run locally in your browser.

Can it handle nested or complex JSON?

Yes. Nested objects and arrays are converted into properly typed interfaces/types.

What if my JSON is invalid?

The generator requires valid JSON. Fix the syntax and run Generate again.