[Home](./index.md) > [@firebase/installations](./installations.md) > [onIdChange](./installations.onidchange.md) ## onIdChange() function Sets a new callback that will get called when Installation ID changes. Returns an unsubscribe function that will remove the callback when called. Signature: ```typescript export declare function onIdChange(installations: FirebaseInstallations, callback: IdChangeCallbackFn): IdChangeUnsubscribeFn; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | installations | [FirebaseInstallations](./installations.firebaseinstallations.md) | The Installations instance. | | callback | [IdChangeCallbackFn](./installations.idchangecallbackfn.md) | The callback function that is invoked when FID changes. | Returns: [IdChangeUnsubscribeFn](./installations.idchangeunsubscribefn.md) A function that can be called to unsubscribe.