JSON to TypeScript Interface Generator
Paste JSON data and instantly generate TypeScript interfaces with nested object support, array type inference, and optional property detection.
When consuming a REST API or working with a JSON configuration file, manually writing TypeScript interfaces is one of the most tedious parts of frontend development. A single API response with 20 fields nested three levels deep can take 15 minutes to type by hand — and a typo in any field name will cause silent bugs at runtime.
This generator analyzes your JSON structure recursively, infers the correct TypeScript types for every field, detects nullable values, and collapses heterogeneous arrays into union types. It even picks a reasonable name for nested interfaces (e.g., UserAddress inside User). Paste your JSON, name your root interface, and get production-ready TypeScript code instantly.