[Home](./index.md) > [@firebase/auth](./auth.md) > [AdditionalUserInfo](./auth.additionaluserinfo.md) > [isNewUser](./auth.additionaluserinfo.isnewuser.md) ## AdditionalUserInfo.isNewUser property Whether the user is new (created via sign-up) or existing (authenticated using sign-in). Signature: ```typescript readonly isNewUser: boolean; ```