Authenticator Extension is described as 'Authenticator generates two-factor authentication (2FA) codes in your browser. Use it to add an extra layer of security to your online accounts' and is a Authenticator in the security & privacy category. There are more than 50 alternatives to Authenticator Extension for a variety of platforms, including Android, iPhone, iPad, Android Tablet and Linux apps. The best Authenticator Extension alternative is Aegis Authenticator, which is both free and Open Source. Other great apps like Authenticator Extension are Proton Authenticator, Ente Auth, Bitwarden Authenticator and 2FA Authenticator (2FAS).