FreeFileSync — The Complete Guide: Free Backup and Sync of Project Folders

FreeFileSync is an open-source tool for comparing and synchronising folders. It shows in advance which files are new, which changed and which were deleted, and copies only what is needed — which turns backing up tens of gigabytes of projects into a matter of minutes.

FreeFileSync

Folder sync and backup — compares folders and copies only what changed, for backing up projects to an external drive.

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Three modes

Mirror — the target becomes an exact copy of the source. Suits backups.
Update — copies new and changed files, without deleting anything on the target.
Two-way — keeps two folders identical, for example at the office and on the laptop.

Safe backups

In mirror mode, a file deleted at the source is deleted from the backup too. So turn on “versioning” — deleted or replaced files are kept in a separate dated folder. Add RealTimeSync to run the backup automatically, and keep at least one copy outside the office. Encrypt a portable backup drive with VeraCrypt.

Related tools

For continuous automatic sync between computers with no cloud — Syncthing. For versions of text files and scripts — Git. A “Donation Edition” adds features such as parallel sync, but the standard version is complete and free.