無料オンラインJSONからTypeScriptへのジェネレーター
APIレスポンスのインターフェースを手書きするのはやめましょう。JSONを貼り付けると、ネストされたオブジェクトが個別の型に分割され、配列要素の形状が自動的に推測されたTypeScriptインターフェースが得られます。
ルートインターフェースに名前を付け、生成されたコードをプロジェクトにコピーし、fetchまたはHTTPクライアントで使用して完全な型安全性を実現します。すべてブラウザでクライアントサイドで実行されます。
Frequently Asked Questions
What TypeScript types are generated?
Primitive JSON values map to string, number, boolean, and null. Arrays become Type[] with the element type inferred from the first item. Objects become interfaces with named properties. Nested objects generate separate interface definitions.
How are optional fields handled?
Properties present in the sample JSON are included as required fields. If you need optional fields, add them to your sample JSON with null values, or manually add ? to the generated interface properties.
Can I name the root interface?
Yes. Set a custom root interface name before generating. Nested interfaces are named automatically based on property names (e.g., Address for an address object).
Does this handle union types?
The generator infers types from a single sample. If a field can be string or number, provide samples that include both variants, or manually adjust the generated type to a union (string | number).
Is the output compatible with strict TypeScript?
Yes. Generated interfaces use standard TypeScript syntax compatible with strict mode. Review nullable fields - JSON null maps to null in the type, not undefined. Adjust to field?: Type | null if needed.