FreeFileSync is a tool intended to synchronize and compare contents between two folders. The program supports various types of locations, including not only local disks but also mapped drives and FTP servers. Moreover, with this tool, you do have any reason to worry about the errors that commonly appear when dealing with long filenames. In a similar way, the program will not fail to transfer locked files.
Two main types of operations are allowed: synchronizing and comparing. When comparing files, the program can identify equal files by examining not only file names but other properties as well. In this regard, it is possible to configure the tool to identify them based on modification time, contents and size. Similarly, you are allowed to use include or exclude filters.
When it comes to synchronizing files, there are three variants available. The first possibility, called two-way synchronization, is characterized by propagating changes on both locations. The second creates a mirror backup of the source folder on the target destination. An update synchronization, in turn, consists in copying new and modified items only. Fortunately, there is the possibility of setting your own rules to create a customized synchronization as well. It is a pity, though, that it cannot perform a smart synchronization, which minimizes the amount of data to transfer and therefore reduces the necessary time.
Finally, it is good news that you can create different jobs including various folder pairs. Likewise, it allows saving work sessions and generating batch jobs, which you can then use to schedule automatic synchronizations using your desired task planner.
In a nutshell, since FreeFileSync is open-source software, it may be the answer for your data backup necessities when you are running on a low budget. However, I must warn you there are more powerful products out there. It is up to you to consider their prices and features to come to a final decision.
v9.2 [Jul 3, 2017]
Use direct copy instead of transaction to speed up versioning
Replaced file existing handling with use of unique temporary names
Support SFTP authentication via Pageant/SSH agent
New menu option to restore hidden panels individually
Fixed GTK button icon being truncated (Linux)
Fixed error dialog hiding behind progress dialog (macOS)
Round out FTP symlink deletion handling
Support four-digit year format on IIS FTP
Fixed FTP parsing error for epoch time on Windows server
Narrow contract for file system abstraction regarding existing files
Treat failure to load database as error rather than warning
Save root folder access for certain FTP path checks
Share images, video and music between your Android and Windows devices