JSON to TypeScript Interface
Generate TypeScript interfaces from a JSON sample — with nested types.
Paste a JSON sample (an object, or an array of objects) and get matching TypeScript interfaces, including nested types for objects and arrays — a huge time-saver when typing API responses. Give the root interface a name and copy the result straight into your codebase. Everything runs in your browser.
Only have a spreadsheet? Turn it into JSON with Excel to JSON or CSV to JSON first.
Frequently asked questions
How do I generate TypeScript interfaces from JSON?
Paste a JSON sample, name the root interface, and click generate to get typed interfaces including nested types.
Why generate types instead of writing them?
Generated types match your data exactly, catch typos, and take seconds — just regenerate when the API changes.
How are arrays typed?
Arrays are typed by their first element, e.g. tags: string[]. Review the type if your array is heterogeneous.
Is my JSON uploaded?
No, everything runs locally in your browser.