Paste JSON to instantly generate matching TypeScript interfaces, with nested objects and arrays handled automatically.
🔒 Your JSON stays on your device and is never uploaded.
Paste a real JSON response or sample payload to instantly generate matching TypeScript interfaces. Nested objects become their own named interfaces, arrays infer their element type, and you can switch between interface and type alias syntax.
Each nested object is extracted into its own named interface, keeping types readable.
Arrays of objects or primitives infer a matching element type, including unions for mixed arrays.
Type inference runs entirely in your browser. Nothing is uploaded.
Each nested object gets its own named interface, generated from the parent key, and is referenced by name in the interface that contains it.
If array items are all the same type, a single element type is used. If they differ, a union type of all observed types is generated.
Yes. Toggle the output style option to switch between interface and type alias syntax.
No. Type inference and generation both run entirely in your browser.