PureSync

I use this synchronization tool as my backup tool for documents & pictures. Not a typical backup tool where you have multiple copy/backup. I think too many copy isn't necessarily a good thing if you can't keep track of what has changed.

• " Synkron " looks promising but keep crashing during analysis step on my ~30GB backup.
• " AllwaySync " is super fast but its analysis result is presented in a big list of file change. It hurt my eye to scroll through the list to see the changes.
• " PureSync " allow me to browse the folder that need to be synced via folder tree view, file list are color coded with side by side comparison, you can make changes directly too.

I like puresync as it can be scheduled. The wizard is easy to understand. When comparing folders it’s easy to read

PRO version copies locked and open files
FREE version does not copy locked or open files.

Home page https://www.puresync.net/
update 29-Sep-2020

4 languages supported, can delete files older than / not modified since xx days:
4 languages: english, german, italian, norwegian.
Since version 2.6.3 you can automatically delete files older than / not modified since xx days, following a specificable pattern, e.g. "TH*.dat;TH*.tmp".

PureSync is the most professional synchronization software that can automatically synchronize the contents of multiple folders, which is free without limitations for private use.
It also is able to delete files and folders automatically in BOTH directions. Some OpenSource Sync products (as FreeFileSync) are not able to cover this function.
The Owner Christoph Güntner of Germany treated my proposals for improvements or new functions always in a very quick and co-operative kind. The developing process of PureSync is very alive, each month one or more new versions.
The most top professional product "Allway Sync" is free only up to 20000 files/month, but it covers more functions than PureSync:
Direct connection to online hard disks (e.g., from the GMX Mediacenter, Amazon S3 or http://mydisk.se) with WebDAV, even if not mapped as a local drive, synchronisation of "Windows Mobile" files on PDA, Smart Phone or SD cards. Backup of Complete "Windows Mobile" PDA or SmartPhone.