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JSON to TypeScript Type Generator

Generate readable TypeScript interfaces from an example JSON payload in your browser.

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Processed locally
Output
Your processed output appears here.

No payload data is uploaded.

Why this tool exists

Work with the structure, not the noise.

Convert a representative JSON object into TypeScript interfaces that are easier to read and refine than a single deeply nested inline type. Nested objects receive stable names based on their parent property, while arrays infer their item type from the supplied values.

01

Generate nested interfaces with readable names

02

Quote keys that are not valid TypeScript identifiers

03

Infer arrays, primitives, objects and nullable values

04

Copy a clean starting point without sending payloads elsewhere

How to use it

From payload to useful result.

  1. Paste an example object

    Use realistic values so primitive and nested types can be inferred accurately.

  2. Name the root type

    Choose a meaningful PascalCase name that matches the API resource or domain model.

  3. Refine the result

    Mark optional properties, replace examples with unions and add shared domain types in your codebase.

Common questions

Before you use the output.

Does the generated type validate runtime data?

No. TypeScript types are removed at runtime. Use JSON Schema, Zod or another runtime validator when inputs are untrusted.

How are empty arrays typed?

They are emitted as unknown[] because an empty sample contains no evidence about the item type.

Keep working locally

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