duplicity vs FreeFileSync

Data is encrypted locally before being sent, and kept encrypted by a key that is never stored on the remote machine. So you might even store your data on a public space, people would still need your key or brute force it.

Duplicity uses the rsync algorithm so only the changed parts of files are sent to the archive when doing an incremental backup. For instance, if a long log file increases by just a few lines of text, a small diff will be sent to and saved in the archive. Other backup programs may save a complete copy of the file.

You can retrieve older versions or files you recently deleted locally even after having updated your backup.

Licensed under GNU GPL v2.

Duplicity does not make many demands on its archive server. As long as files can be saved to, read from, listed, and deleted from a location, that location can be used as a duplicity backend. Besides increasing choice for the user, it can make a server more secure, as clients only require minimal access.

Docker allows to run programs on any Linux without having to really install them, and allows to manage versions so it runs exactly the same on different machines.

It will work with MTP, FTP, SFTP, FTPS, and more.

It supports Volume Shadow Copy Service, meaning that it can copy files even if they are in use or otherwise locked.

It runs on Windows, Linux and MacOS.

FreeFileSync provides direct access to Google Drive, no additional software is needed.

Source code releases are provided under GPLv2.

It can be configured to constantly monitor two folders for changes and sync them instantly when a change is detected.

You can program your own jobs for execution as a script.

For Unix-like systems.

It can copy files and folders with more than 260 characters in their paths.

Versioning is keeping multiple instances of the modifications of your files.