JSON to TypeScript Interface Generator

Generate a TypeScript interface from a real JSON sample so you can type an API response without writing every field by hand. This tool parses your JSON, infers the type of each value, and emits named interfaces for nested objects, recursing as deep as your data goes. Arrays are typed by inspecting their items, mixed types become a union, and empty arrays fall back to a safe any array. Nested objects get their own PascalCase interface named after the key, and keys that are not valid identifiers are quoted. Paste a representative JSON object, set the root type name, click generate, and copy the interfaces straight into your project. Everything runs locally in your browser, so the sample data you paste never leaves your machine or gets logged by any service.