FreeFileSync is a folder comparison and synchronization software that creates and manages backup copies of all your important files. Instead of copying every file every time, FreeFileSync determines the differences between a source and a target folder and transfers only the minimum amount of data needed. FreeFileSync is Open Source software, available for Windows, Linux and macOS. .

FreeFileSync

Open Source File Synchronization

• During comparison FreeFileSync groups all folders by their root devices
• For example, consider a configuration with two folder pairs and parallel file operations set up: C:\Source ↔ D:\Target C:\Source2 ↔ E:\Target Device root Parallel operations C:\ 1 D:\ 2 E:\ 3 FreeFileSync will put the folders C:\Source and C:\Source2 into the same group and allow only 1 file operation at a time
• Folder D:\Target will be traversed using 2 operations, and E:\Target using 3 operations at a time
• In total FreeFileSync will be scanning all four folders employing 6 file operations in parallel
• When synchronizing a folder pair FreeFileSync will use the maximum of the number of parallel operations that the two folders support
• In the previous example the folder pair C:\Source ↔ D:\Target will be synchronized using 2 parallel operations, and C:\Source2 ↔ E:\target will be using 3