What does the JSON to TypeScript tool do?

It converts any valid JSON object or array into TypeScript interfaces or type aliases. Paste your JSON on the left and see clean, ready-to-use TypeScript types on the right — instantly.

Does it handle nested objects and arrays?

Yes. Nested objects are extracted into separate named interfaces (e.g., UserAddress, OrderItem[]). Arrays of objects produce typed array definitions, and mixed-type arrays become union types.

Can I generate type aliases instead of interfaces?

Absolutely. Toggle the 'Type Alias' option to switch from interface Foo {} to type Foo = {}. Both outputs are fully valid TypeScript.

Is my JSON data sent to any server?

No. Everything runs entirely in your browser using JavaScript. Your JSON is never transmitted, stored, or logged anywhere. It's safe to paste sensitive API payloads.

What happens with optional properties?

When 'Optional Properties' is enabled and your input contains an array of objects, any key that doesn't appear in every object is marked as optional (key?: Type). For a single object, all keys are required by default.

Can I add the export keyword to interfaces?

Yes — toggle 'Export Types' and every generated interface or type alias is prefixed with export. This lets you paste them directly into a .ts module file.

Free TypeScript Tool

Turn JSON into
TypeScript Types

Paste any JSON and get clean TypeScript interfaces or type aliases in seconds. Supports nested objects, arrays, optional fields, and union types — 100% browser-based, zero data sent.

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Nested Objects

Deeply nested JSON structures are converted to properly named, hierarchical TypeScript interfaces automatically.

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Real-Time Output

As you type or paste JSON, TypeScript types are generated instantly — no button to click, no waiting.

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100% Private

All processing happens in your browser. Your JSON never leaves your device — safe for sensitive API payloads.

Options:

Root name:

📥 JSON Input

TypeScript Output

TypeScript interfaces will appear here…

Frequently Asked Questions

Everything you need to know about JSON to TypeScript.

Turn JSON into TypeScript Types

Nested Objects

Real-Time Output

100% Private

Frequently Asked Questions

Turn JSON into
TypeScript Types