TSJSON → TypeScript
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TypeScript's static type system requires you to define interfaces or types for your data structures. Writing these by hand from API response JSON is tedious and error-prone, especially with deeply nested objects. This tool automatically generates TypeScript interfaces or type aliases from any JSON payload, handling nested objects, arrays, and null values.
How to Use
- 1Paste JSON
Paste the JSON you want to convert on the left. Click 'Load Example' to try a sample with nested objects and arrays.
- 2Configure Options
Set the root interface name, output style (interface or type alias), whether to include the export keyword, and how to handle null values.
- 3Copy Result
Review the generated TypeScript on the right and click the copy button to use it in your project.
Tips
- 💡Nested JSON objects are automatically converted to separate named interfaces or types.
- 💡Fields with null values are typed as 'T | null' when the null option is enabled, keeping your code null-safe.
- 💡Empty arrays ([]) produce unknown[] — update the type manually once you know the element shape.
- 💡Paste an API response JSON to instantly scaffold the response type for your TypeScript project.
FAQ
- Q. What are the benefits of generating TypeScript interfaces from JSON?
- A. Typed interfaces enable compile-time error checking, IDE autocomplete, and safer refactoring. They make it clear what shape your API responses should have.
- Q. Does the tool generate interface or type alias?
- A. It generates interface declarations by default. You can rename the keyword to type if needed. The main practical difference is that interfaces support declaration merging while type aliases do not.
- Q. How are arrays in JSON represented in TypeScript?
- A. JSON arrays are converted to T[] or Array<T> where T is inferred from the array elements. If the array is empty, the type defaults to unknown[] or any[].