INPUT - JSON
OUTPUT - TypeScript
Output will appear here
100% client-side
Output will appear here
Convert JSON to TypeScript interfaces in one click with our free online JSON to TypeScript converter. The tool infers proper types for every field, generates named interfaces for nested objects, and supports strict-mode-compatible output. Ideal for front-end developers who need typed API response models without writing boilerplate.
Try Convert All - paste JSON once, see TypeScript, Go, YAML, and 15 more formats instantly.
Enter a JSON object or array in the left editor, or fetch JSON from a URL. The converter accepts any valid JSON structure including deeply nested data.
The right pane instantly displays TypeScript interfaces with properly inferred types for strings, numbers, booleans, arrays, and nested objects.
Click Copy to place the interfaces on your clipboard, or download the generated code as a .ts file ready to drop into your project.
The converter produces string, number, boolean, null, and nested interface types. When an array holds mixed primitives it creates a union type such as string | number. Date-like strings remain typed as string since TypeScript interfaces describe raw JSON shapes.
Yes. Every nested object generates its own named interface, and the parent interface references it by name. This keeps code clean and avoids inline type literals, even for three or four levels of nesting.
Absolutely. Use the URL-fetch button to pull a live JSON response from any public API endpoint. The converter will parse the response and produce TypeScript interfaces immediately, saving you from writing types by hand.
Yes. The output is fully compatible with TypeScript strict mode, including strictNullChecks. Nullable fields are expressed as optional properties so your compiler will flag any unchecked access.
Top-level objects use the name "Root" by default. Nested objects are named after their parent key in PascalCase. For example, a key called "shipping_address" produces an interface named ShippingAddress.