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JSON to TypeScript
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Convert JSON to TypeScript interfaces online
This JSON to TypeScript converter generates clean, ready-to-paste TypeScriptinterface definitions from any JSON sample. Nested objects become their own named interfaces, arrays are typed from their elements, and null values are typed as nullable. It's the fastest way to add type safety around an API response without writing every property by hand.
Why generate TypeScript types from JSON?
Hand-writing interfaces for large API payloads is slow and error-prone - one typo in a property name and your compiler happily accepts broken code. Generating TypeScript types from a real JSON responseguarantees the shape matches what the server actually sends. That gives you autocomplete in your editor, compile-time checks on refactors, and self-documenting code for teammates.
What the generator handles
- Nested objects - each becomes a separate named interface.
- Arrays of objects, primitives and mixed values.
nullvalues - typed as| nullso you remember to handle them.- Property names that need quoting (e.g.
"first-name").
Everything runs locally in your browser using plain JavaScript - the JSON you paste is never uploaded. Building a .NET backend too? Try the JSON to C# converter, or validate your payload first with the JSON validator.