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JSON to TypeScript

Paste JSON and get clean TypeScript interfaces — nested types, arrays and optional fields.

Root name
JSON input
TypeScript output

      

    

    

    

  


  

    
About this tool

    
Free online JSON to TypeScript converter

    
The Ajenza JSON to TypeScript converter reads a JSON sample and generates matching TypeScript interfaces. Nested objects become their own named interfaces, arrays become typed arrays (merging object shapes into one interface), and values that vary become union types. When objects in an array don't all share the same keys, the missing keys are marked optional. Use it to bootstrap API response types from a real payload. Nothing is uploaded — it all runs in your browser.

    
Frequently asked questions

    
Is it free?
Yes — completely free, with no sign-up, download or watermark.

    
How are arrays typed?
The element types across the array are merged: objects into a single interface (with optional keys where they differ), primitives into a union.

    
Is my JSON uploaded?
No — parsing and conversion run entirely in your browser.

    
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