Google Duo Alternatives for Mac OS X

Skype is a versatile communication platform offering free voice and video calls to other Skype users, as well as affordable calls to landlines and mobile phones worldwide. It provides instant messaging, file sharing, and screen sharing features, making it a comprehensive tool for personal and professional connectivity across various devices.

WhatsApp Messenger is a widely used free messaging and calling app, available globally. It enables communication through text, voice messages, and video calls, facilitating connections between individuals and groups across various devices and platforms.

Tox is a free, open-source, and secure peer-to-peer instant messaging and video calling protocol designed for strong privacy and censorship resistance. It provides end-to-end encrypted communications without reliance on central servers.

Signal is a secure, open-source messaging application that uses end-to-end encryption to protect user communications. It offers text messaging, voice and video calls, group chats, and file sharing, all with a strong focus on privacy and security. Available on multiple platforms, Signal is a leading choice for individuals prioritizing confidential conversations.

Linphone is a free and open-source Voice over IP (VoIP) application and SIP client available on multiple platforms. It enables encrypted voice and video calls, instant messaging, and file sharing, offering a privacy-focused communication solution.

Wire is a secure, cross-platform messaging and collaboration client offering end-to-end encryption by default for all communication types including messaging, voice and video calls, and file sharing across desktop and mobile devices.

FaceTime is Apple's integrated video and audio calling service, providing a seamless communication experience across Apple devices. It allows users to connect with friends and family through high-quality video and audio calls, including group conversations.