Messenger for Desktop is a third-party chat and VoIP application. It allows Windows and macOS users to connect with other Facebook users outside of a web browser. At 3MB, it is a lightweight program for Windows devices running Windows 7, 8, and 10. It can also run on Mac computers running macOS 10.10 or newer. It has features that make it unique from the official Facebook Messenger application. These include themes, spell check, and autocorrect. It also supports keyboard shortcuts, launch on startup, and desktop notifications. As an unofficial Facebook app, it does not store your messages or personal data in a server.