If you're looking for a file syncing program with the most options and greatest flexibility, you can't go wrong with GoodSync. Running out of characters, but I can't recommend FFS highly enough.Can get confusing with all the available settings. Another plus is that you must 'Compare' the source-destination before you can ' Syncronize', and this preview is very easy to understand (and includes clear visual aids) as to what will be copied and-or deleted. Also, drag-and-drop for source and destination files-folders-drives and automatic ignoring of RECYCLE.BIN, RECYCLER, etc makes things simpler. The program is remarkably intuitive, as the interface is very clean and hovering the cursor over any button or area of importance opens a tool tip. The first time I used FreeFileSync I was amazed at its combination of ease of use and functionality. Eventually I became comfortable with its use but also discovered that the free edition doesn't have Unicode support (a problem for files with odd or foreign names). At first I found SyncBack quite intimidating: so many buttons, so many options, even more advanced options. When I first went looking for a freeware sync program, I settled on SyncBack after hours of searching and reading reviews. Within a day SyncBack was uninstalled and FreeFileSync was put into the folder where I keep all my stand alone applications and a desktop shortcut was created to fill the void left by SyncBack's recently departed icon.

After using the free edition of SyncBack for a couple of years to keep several sets of entire external hard drives-as well as some folder combinations-syncronized, I recently bumped into FreeFileSync.

Freefilesync google drive