TypeScript tool
Paste an API payload or a config file. Nested objects become named interfaces, arrays merge optional keys, and files stay on this device.
Like the tool? Find a bug?Share with usPaste JSON. Nested objects become named interfaces. Missing keys in arrays become optional. Files stay on this device.
TypeScript will appear here.Guide
01
Objects become interface (or type) declarations. Nested objects get PascalCase names from their keys.
02
Sample, Nested, and Array are starting points. Parsing stays local — paste a response body and copy types.ts.
03
Array items are merged. A key that appears in only some objects becomes optional. Mixed primitives become a union like string | number.
Use it
Objects, nested objects, arrays of objects, primitive arrays, null, and quoted keys that are not valid identifiers. Empty arrays become unknown[]. Invalid JSON shows a parse error. The 50,000 character cap still applies.
FAQ
Interface is the default and matches typical API models. Switch to Type for type Name = { … } aliases. Export prefixes declarations; Local omits it.
When you paste an array of objects, this tool unions their shapes. A property missing from some items is marked with ?.
No. Parsing happens in your browser tab. There is no account and no API call.