FreeFileSync: powerful folder comparison and synchronization tool


FreeFileSync is a free/open source folder and file synchronization program that features a beautiful, two pane user interface and a host of powerful options.

It can do the following: compare files by their content or by file size and date, synchronize files and subfolders, process multiple pairs of folders at once, load/save folder comparison sessions, create batch jobs that can be run from the command line, and can can handle cloned files (i.e. symbolic links or junctures). It also offers UniCode and Network support. There is also a portable (no-install) version.

Do you need a directory comparison and synchronization program with a lot of features and options? If so then you’ve just found one of the best free programs in its class. Before I continue I will point out that for this review I will use a mock question-and-answer format where I pretend I am being interviewed by someone else 🙂

Q: You’ve said that this is one of the best directory comparison apps. Why do you like it so much?
A: I like that it supports so many advanced options. But there are three real reasons:

  1. The interface: this program’s Graphical User Interface is just tremendous. It looks good and delivers a great user experience in the way the items are compared are presented visually, and each entry has a little button that can be used for individual on-the-fly syncing.
  2. Supports multiple folder comparisons simultaneously: which means you can perform all your folder comparisons and synchronizations at once and be done with it. You can also save your sessions (which the program calls “configurations”), to quickly re-do the comparisons at a future point in time.
  3. FreeFileSync batch filesCan create automated “batch files” for folder syncing: these can be run from the command line, and will allow you to specify folder(s) to compare, rules for syncing, file extension filters, and other details (see image to the right).

Q: How does this program determine which files are different and which files are the same?
A: It lets the user decide whether it should compare the actual content of the files or whether to simply compare the size and date of files.

FreeFileSync sync typesQ: Does it support 2-way synchronization?
A: Yes. It supports “Mirror syncs” (right folder will exactly match the left, no matter what’s in it), “Update syncs” (new/updated files will be copied to the right folder), and “Two-way syncs” (both sides will be changed to reflect the new or updated files that are found on either side). Deletions ca an be performed via the Recycle Bin, which gives the user recourse to go and salvage them if need be, and copy errors can be ignored if necessary as well.

There is a also a so called custom sync option where users can create their own syncing rules, but it does not seem to be active as of the version I tested.

FreeFileSync file filtersQ: Is it possible to only compare certain file extensions, or specify extensions that should NOT be compared?
A: Yes. You can do either one of the above, i.e. specify what to include or specify what to exclude (see image to the right for an example where I am excluding ZIP, RAR and JPG files from processing). You can also use the context menu for some quick, on-the fly file extension filtering. It is also very easy to hide or show filtered items from the main display interface.

Q: You mentioned other “advanced options” that this program supports. Can you list some of these?
A: Supports filesizes larger that 4GB, no limitations on number of files, “delete before copy” to avoid disc space shortages with large sync operations, handling of cloned files (i.e. symbolic links or junctures), UniCode and Network support.

Q: So what’s the verdict? Any last remarks.
A: Excellent Program. I was looking for a program that can compare two folders (and subfolders) when I found this and it was so much more that I expected. I highly recommend it.

I also would like to mention that there is a portable version available. Simply download the zipped version and extract it where you want it, even on a USB drive.

Freewaregenius 5-Star Pick

Version Tested: 2.1 build July 3 2009 Unicode

Compatibility: WinAll.

Go to the program page to download the latest version (approx 1.3 megs).