JSON to TypeScript Converter
Generate accurate TypeScript interfaces from any JSON sample.
Generate TypeScript Types from JSON
Stop hand-writing interfaces for your API responses. Paste a sample JSON payload and this tool infers a complete set of nested, strongly-typed TypeScript interfaces you can drop straight into your codebase.
Smart inference
- Nested objects become their own interfaces
- Arrays infer element types, including unions
- Numbers, strings, booleans, and null are detected
- Object keys are converted into PascalCase type names
Why generate types
Strong typing catches mistakes at compile time, powers editor autocomplete, and documents the shape of your data. Generating from a real response keeps your types perfectly in sync with the API.
Tips for best results
Provide a representative payload that includes every field, ideally with non-empty arrays so element types can be inferred. For fields that are sometimes null, include both a populated and a null example, and the generator will produce a union type.
100% Private & Processed Locally
Every conversion on this page runs entirely inside your browser using JavaScript. Your data is never uploaded to a server, logged, or stored â making this tool safe even for sensitive payloads such as API responses, configuration files, and access tokens.
Because there is no network round-trip, conversions are instant and work even when you are offline. It is free to use with no sign-up, no rate limits, and no ads injected into your output.
Frequently Asked Questions
Common questions about the JSON to TypeScript Converter.