All tools

JSON to TypeScript Interface Generator

Paste any JSON object and get fully typed TypeScript interfaces instantly. Handles nested objects, arrays, optional fields, and union types. Runs entirely in your browser — no data sent anywhere.

Load an example:

JSON input
TypeScript interfaces
// TypeScript interfaces will appear here

Get TypeScript CLAUDE.md rules

Browse community rules for TypeScript strict mode, path aliases, type safety, and more.

Browse TypeScript rules

Why use TypeScript interfaces?

TypeScript interfaces provide compile-time type checking for your data structures. When working with API responses, database records, or configuration objects, having accurate interfaces catches bugs before they reach production and improves code editor autocompletion.

How the converter works

  • Nested objects become named sub-interfaces (e.g., a "pricing" key becomes a Pricing interface)
  • Arrays infer element types — mixed arrays become union types
  • Null values mark fields as optional with a ? modifier
  • Non-identifier keys are quoted automatically