JSON to TypeScript Converter Online — Generate TS Interfaces

Convert any JSON object or array into strongly-typed TypeScript interfaces. Supports nested objects, optional fields, and array unions. Runs 100% locally in your browser.

Open JSON to TypeScript Converter →

How to convert JSON to TypeScript

  1. Paste your JSON document into the workbench.
  2. Open the Types panel from the toolbar or press ⌘ K.
  3. Set root interface name (default: Root).
  4. Copy generated TypeScript code or download the .ts file.

Nested Interfaces

Automatically splits complex nested objects into clean, reusable child interfaces.

Array Unions

Handles mixed-type arrays and extracts unique item types (e.g. (string | number)[]).

Local & Secure

Generates types in Web Worker without uploading code to any server.

Frequently Asked Questions

How do I convert JSON to TypeScript interfaces?

Simply paste your JSON into the workbench, open the Types panel, and copy the generated TypeScript interface definitions instantly.

Does this tool upload my data?

No, type inference runs entirely in your browser using a local Web Worker.