FreeFileSync 6.9

It allows you to both compare and synchronize the contents of two folders
4.5  (35 votes)
9.1 (See all)

FreeFileSync is a handy utility that allows you to both compare and synchronize the contents of two folders. The program offers editions for three of the most popular operating systems – MS Windows, Linux, and MacOS. Besides, this is an open source tool, which means that anybody can use it free of charge, though you can always make a donation if you like it.

The program's multilanguage user interface may be a bit confusing at first, especially for beginners. It asks you to select the two folders you want to compare or synchronize, which can be done by using the Browse dialog included or by dragging them from Windows Explorer. Next, you can open the Settings windows to configure the comparison settings, the synchronization settings, and the filters. For the comparison function, you can select between two methods – "File time and size", which is faster, or "File contents", which is slower but more precise. As for the synchronization function, you can also select among several variants: Two-Way, Mirror, Update, and Custom. You can also select a destination for the deleted files – permanent deletion, the recycle bin, or the versioning system.

As I stated before, the program also allows you to filter the results of a folder comparison. In this case, you need to define exclude and include lists, where you can use wildcards to create a precise definition. You can filter the files by name, extension, subfolder, size, and other parameters. Now you can compare your folders, check the differences between them, and start the synchronization process. There is also an overview panel, where you can see the folder tree corresponding to your comparison job.

Finally, FreeFileSync comes with a complementary app called "RealTimeSync". Basically, this app monitors one or more folders and executes a specific command line when they become available (e.g., when you re-connect a pen drive). Normally, the command line is used to execute a synchronization batch job, which can be created using FreeFileSync’s main interface.

All in all, FreeFileSync is a great tool that allows you to synchronize your folders without too many complications. If, for example, you have your photo collection scattered across several folders, you can use FreeFileSync to organize it and, at the same time, to create a backup of it. Best of all, the program is totally free, even for commercial use.

Ricardo Soria
Editor rating:

Review summary


  • Multilanguage interface.
  • Offers you two comparison methods.
  • Offers you four synchronization methods.
  • Includes the "RealTimeSync" complementary app.
  • Capable of keeping versioned copies of the deleted files


  • It may be a bit hard to use at first for beginners
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