[Home](./index.md) > [@firebase/auth](./auth.md) > [useDeviceLanguage](./auth.usedevicelanguage.md) ## useDeviceLanguage() function Sets the current language to the default device/browser preference. Signature: ```typescript export declare function useDeviceLanguage(auth: Auth): void; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | auth | [Auth](./auth.auth.md) | The Auth instanec. | Returns: void