How do I generate TypeScript interfaces from JSON?

Paste your JSON in the left panel. TypeScript interfaces are generated instantly in the right panel. Nested objects become separate named interfaces. Click 'Copy Output' to copy the result.

What JSON structures are supported?

The generator supports JSON objects (converted to interfaces), arrays (infers element type), nested objects (each becomes a named interface), and all JSON primitives: string, number, boolean, and null.

Is the JSON to TypeScript generator free?

Yes, completely free. Type generation runs entirely in your browser — no data is sent to any server, and no signup is required.

JSON to TypeScript Interface Generator

Generate TypeScript interfaces from JSON instantly online. Free JSON to TypeScript converter with nested object support, array types, and proper type inference.

JSON Input

TypeScript Output

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How to Use the JSON to TypeScript Generator

Paste your JSON object or array in the left panel.
TypeScript interfaces appear automatically in the right panel.
Click "Copy Output" to copy the interfaces to your clipboard.
Use "Download" to save the result as a .ts file.
Use "Load Example" to see a sample with nested objects and arrays.

How Types Are Inferred

JSON strings → string
JSON numbers → number
JSON booleans → boolean
JSON null → null
JSON arrays → element type with [] suffix
Nested JSON objects → separate named interfaces in PascalCase