FreeFileSync - FreeFileSync is a free open source data backup software that helps you synchronize files and folders on Windows, Linux and macOS.
Online Vault Backup - Online Vault Backup is a cloud storage service that allows you backup your data while having unlimited storage.
SyncBack - Backup software for the PC: powerful, easy to use solution for backing up and synchronising files on a local/network drive, the cloud, FTP server and more.
Rebel Backup - Rebel Backup lets you make encrypted backups of your important files to Dropbox or Google Drive.
Compare Advance - Compare Advance makes comparing any two folders an easy job.
Duplicati - Free backup software to store backups online with strong encryption. Works with FTP, SSH, WebDAV, OneDrive, Amazon S3, Google Drive and many others.