rsync is described as 'File and directory synchronization tool for Unix systems with delta encoding, compression, recursion, SSH support, permission preservation, and flexible filters' and is a very popular File Sync tool in the backup & sync category. There are more than 100 alternatives to rsync for a variety of platforms, including Windows, Mac, Linux, Android and BSD apps. The best rsync alternative is Syncthing, which is both free and Open Source. Other great apps like rsync are FreeFileSync, TeraCopy, Rclone and Duplicati.