JSON to TypeScript
FreeGenerate TypeScript interfaces from JSON objects
interface Root {
id: number;
name: string;
active: boolean;
}About JSON to TypeScript
When you consume a JSON API in a TypeScript project, you want types so the compiler catches mistakes and your editor autocompletes fields. Hand-writing interfaces for a large or deeply nested response is tedious and drifts out of sync with the data. This tool reads a JSON sample and generates matching TypeScript interfaces so you get typed access from the start.
Paste a representative JSON object and the converter infers each field's type, creating nested interfaces for nested objects and typing arrays from their elements. It is free, runs in your browser, needs no signup, and returns the interfaces instantly. Because types are inferred from one sample, give it a complete, representative example, and review optional or nullable fields the sample may not cover.
Common uses
- Generating TypeScript interfaces for an API response you consume
- Typing a JSON config or fixture in a TypeScript project
- Creating types for a nested JSON payload without writing them by hand
- Bootstrapping models from a sample response to refine later
- Keeping editor autocomplete and type checks aligned with your data
How to use
- 1
Configure options
Set your preferences using the options panel below.
- 2
Click Generate
Click the process button to generate your result instantly.
- 3
Copy or download
Copy the result to clipboard or download it directly to your device.
Why ToolHub?
- Accurate conversion
- Multiple formats
- Instant results
FAQ
How are nested objects typed?
Nested objects get their own generated interfaces, which are referenced from the parent, so the structure stays readable and reusable.
Can it detect optional fields?
Types are inferred from the sample provided, so fields missing or null in the sample may need you to mark them optional or nullable.
How are arrays handled?
Array element types are inferred from the items present. Mixed-type or empty arrays may produce broad types you can tighten.
Should I provide one object or many?
A single complete, representative object works well. For arrays, the element shape is what drives the generated interface.
Can I use JSON to TypeScript on mobile?
Yes — ToolHub is fully responsive and works on iPhone, Android, tablets and all modern browsers. No app install needed.