How to use

Generate TypeScript from JSON before you write models by hand

The JSON to TypeScript converter inspects objects and arrays in your browser and emits interfaces or type aliases. Use it when you need a fast starting point from an API payload.

Open JSON to TypeScript

Paste a real payload

Use a response body, fixture, or config file. Nested objects and arrays give better types than a single flat record.

Name the root type

Set a root name that matches your domain, such as User, Order, or Invoice. Nested keys become their own interfaces.

Review optional fields

If objects in an array do not share every key, missing keys are marked optional so the type stays honest.

Copy into your project

Export interfaces or type aliases, paste them next to your API client, then keep JSON Viewer nearby for the next payload.

Practical typing tips

Prefer a sample that includes both filled and missing fields so optional keys are inferred.
Null stays null in the union. Replace it with a tighter type if your API never returns null in production.
Empty arrays become unknown[]. Add one example item when you know the element shape.
This tool does not validate runtime data. Pair types with a schema if you need checks at the boundary.