What is JSON to TypeScript?

JSON to TypeScript generates accurate TypeScript interfaces and type definitions from JSON data. It infers types for strings, numbers, booleans, arrays, and nested objects, handling optional fields and union types — saving hours of manual type writing for API responses.

How to use

1. Step 1 — Paste a JSON object or array. The tool analyzes the structure and infers TypeScript types for every field.
2. Step 2 — Customize the output: set the root interface name, choose between interfaces and type aliases, and toggle optional properties for fields that may be null.
3. Step 3 — Copy the generated TypeScript definitions or download as a .ts file. All nested objects get their own named interfaces automatically.

Result

Your API returns a user object with nested address and preferences. Paste the JSON response, set root name to 'User', and get clean interfaces: User, UserAddress, UserPreferences — with correct types like 'string | null' for optional fields.

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