How does it handle nested objects?

Each nested object becomes its own named interface. Property names are used to generate meaningful interface names.

What happens with arrays of mixed types?

Mixed-type arrays generate union types (e.g., (string | number)[]). Empty arrays default to unknown[].

Can I customize the root type name?

Yes. Enter any valid TypeScript identifier and all generated types will use it as the root.

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JSON to TypeScript

Generate TypeScript interfaces from JSON data

Root Interface Name

Output Type

interfacetype

JSON Input

About JSON to TypeScript

What is JSON to TypeScript?

Generate TypeScript interfaces or type aliases from any JSON payload. Handles nested objects, arrays, null values (as optional fields), and mixed types. Customize the root type name and output format.

Features & Benefits

Instantly generate TypeScript interfaces from any JSON
Handles deeply nested objects and complex array types
Detects optional fields from null values automatically
Toggle between interface and type alias output
Syntax-highlighted output with one-click copy
100% client-side — your data stays private

Frequently Asked Questions

How does it handle nested objects?: Each nested object becomes its own named interface. Property names are used to generate meaningful interface names.
What happens with arrays of mixed types?: Mixed-type arrays generate union types (e.g., (string | number)[]). Empty arrays default to unknown[].
Can I customize the root type name?: Yes. Enter any valid TypeScript identifier and all generated types will use it as the root.

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