JSON to TypeScript
JSON to TypeScript
Generate TypeScript interface definitions from any JSON sample with correct types inferred automatically.
How to Use JSON to TypeScript
- 1.Paste your JSON Paste a representative JSON sample - object, array of objects, or nested structure.
- 2.Set interface name Enter a name for the root interface (defaults to 'Root').
- 3.Click Generate TypeScript interface definitions are generated with correct types for all fields.
- 4.Copy the interfaces Copy the TypeScript and paste directly into your project.
JSON to TypeScript & JSON Developer Standards
JSON is the standard format for web APIs and modern applications. Using the JSON to TypeScript helps you check syntax, catch formatting errors, and keep your data clean and readable.
Zero-Server Security
All data entered into JSON to TypeScript runs directly inside your browser sandbox. Nothing is ever sent across the network or saved on remote servers.
Clean & CI/CD Ready
Well-formatted JSON prevents runtime syntax bugs, makes code reviews easier, and ensures smooth API data exchange.
JSON to TypeScript Frequently Asked Questions
How does the type inference work?
The generator inspects each value in the JSON sample to determine its TypeScript type: string, number, boolean, null, arrays (with inferred element type), and nested objects (as named interfaces). Union types are used when a value could be multiple types across different samples.
What happens with nullable fields?
Fields that are null in the sample are typed as the inferred type | null. If you want optional fields (property?: Type), there is an option to mark nullable or missing fields as optional.
Can it generate types for arrays of objects?
Yes. An array of objects generates an item interface and the parent property is typed as ItemInterface[]. Nested arrays and objects of any depth are all handled.
Should I use interface or type?
The tool generates interface declarations by default. You can switch to type aliases in the options. Interfaces are generally preferred for object shapes in TypeScript as they support declaration merging and produce clearer error messages.
Can this tool handle large, complex JSON payloads?
Yes. Because the tool operates directly inside modern V8 JavaScript execution engines, it easily processes complex multi-megabyte payloads containing thousands of nested keys with negligible latency.
Are my proprietary payloads or secrets stored or cached?
No. BeYourTools implements zero tracking, zero telemetries, and zero database persistence. Everything stays strictly inside your browser memory and disappears the moment your tab is closed.