TypeScript wants types, and your data usually starts as JSON. This page closes that gap: paste a JSON sample and it generates a json to typescript interface in your browser, free, with each field inferred from the data. The whole json to ts pass stays on your device.
A sample in, an interface out.
Paste a representative JSON object and the tool reads every field, then writes matching TypeScript. Strings become string, numbers become number, nested objects become nested interfaces, and arrays with mixed values become union types. You name the root, and it gives you a ready json to typescript interface.
People look for this as json to typescript or the shorter json to ts. The value is accuracy: instead of hand typing an interface and missing a field, you get types generated straight from real data, which is faster and less error prone.
Two common mix-ups.
TypeScript types are not the same as a JSON Schema. This page does not act as a json schema converter or a json to schema converter, since a schema describes validation rules rather than TypeScript types. If you need that, it is a different output format entirely.
It also does not convert code. A js to ts converter online, or a tool to convert javascript to typescript online, transforms actual JavaScript files. This page takes a JSON sample as input and describes its shape, so reach for it when you have data rather than code.
When your JSON arrives messy.
Sometimes the JSON shows up as an escaped string from a log or an API field. The JSON Formatter handles json string to json and works as a json formatter online free, so you can tidy and validate the data there, then paste the clean version here to generate types from a sample you trust.
Try it now
The tool is one click away. No sign up, no upload, no payment.
Open JSON to TypeScript