Common Error Codes

auth/account-exists-with-different-credential

Thrown if there already exists an account with the email addressasserted by the credential. Resolve this by callingfirebase.auth.Auth.fetchSignInMethodsForEmail with the error.emailand then asking the user to sign in using one of the returned providers.Once the user is signed in, the original credential retrieved from theerror.credential can be linked to the user withfirebase.User.linkWithCredential to prevent the user from signingin again to the original provider via popup or redirect. If you are usingredirects for sign in, save the credential in session storage and thenretrieve on redirect and repopulate the credential using for examplefirebase.auth.GoogleAuthProvider.credential depending on thecredential provider id and complete the link.

auth/credential-already-in-use

Thrown if the account corresponding to the credential already existsamong your users, or is already linked to a Firebase User.For example, this error could be thrown if you are upgrading an anonymoususer to a Google user by linking a Google credential to it and the Googlecredential used is already associated with an existing Firebase Googleuser.The fieldserror.email,error.phoneNumber, anderror.credential (firebase.auth.AuthCredential)may be provided, depending on the type of credential. You can recoverfrom this error by signing in witherror.credential directlyviafirebase.auth.Auth.signInWithCredential.

auth/email-already-in-use

Thrown if the email corresponding to the credential already existsamong your users. When thrown while linking a credential to an existinguser, anerror.email anderror.credential(firebase.auth.AuthCredential) fields are also provided.You have to link the credential to the existing user with that email ifyou wish to continue signing in with that credential. To do so, callfirebase.auth.Auth.fetchSignInMethodsForEmail, sign in toerror.email via one of the providers returned and thenfirebase.User.linkWithCredential the original credential to thatnewly signed in user.