What are the basic steps to use FreeFileSync?
For the most up to date description of FreeFileSync, visit the Online Manual. Press F1 while running FreeFileSync.
If internet access is not available, an offline version of the manual can be found in the FreeFileSync installation folder.
After you've become comfortable with using FreeFileSync, read chapter Tips and Tricks for more fun!
FreeFileSync runs natively on all 32 and 64-bit Windows versions.
FreeFileSync runs on all recent 64-bit editions of macOS.
FreeFileSync is supported on all major Linux distributions.
|Microsoft Windows||Apple macOS||Linux|
FreeFileSync imposes no artificial limitations on how many files you can sync. Practically speaking, the only limiting factor for extremely large sync jobs is the amount of free memory available: For each 1 GB of RAM FreeFileSync can synchronize roughly 1.7 million file pairs at a time.
Yes, FreeFileSync may be used in business, commercial, and government environments without cost.
You are permitted to distribute the software subject to the following conditions:
Do I need to uninstall FreeFileSync before installing a newer version?
No, you can safely install a new version of FreeFileSync into a directory that contains an old version. FreeFileSync will recognize the previous installation and clean up thoroughly should you choose to uninstall at a later time.
FreeFileSync is designed for local installation and provides the best user experience in this variant.
In order to support restricted scenarios, FreeFileSync also allows for portable installation on USB memory sticks or external hard drives. However part of FreeFileSync's functionality may not be available in this case: For example it won't be possible to manage FreeFileSync configuration files via context menu in Windows Explorer or start batch runs with a few mouse clicks. Therefore local installation is recommended in general.
The FreeFileSync installer is showing a single advertisement (and only during installation) to help recover part of the software development effort, which is the time and energy invested in application design, implementation and continuous support. Although it's nowhere near enough to allow to focus on FreeFileSync full time, it is more effective than asking for donations only. If nothing else it helps keep the motivation for the project, next to the other big motivation: striving for perfection in software design.
No, FreeFileSync never installs anything without consent. During installation you are provided a single offer screen. If you want to support the FreeFileSync development or find the software that is shown useful, feel free to accept the offer. If not, just decline and nothing other than FreeFileSync will be installed.
|Sync files without limits|
|Portable version (ZIP)|
The normal FreeFileSync Donation Edition may be used and installed by a single home user on his computer.
This includes installation on portable storage devices (USB memory sticks) and even use on different computers,
provided that FreeFileSync was already activated (during first start) on the former computer.
However if the portable installation files are copied to a different computer (instead of being used directly from a memory stick), this is considered a second installation.
In order to obtain the FreeFileSync Donation Edition licensed for multiple users/installations, please use the donation button here on the side.
No, the FreeFileSync installer never contains malware or viruses. Both firewalls and virus scanners work with heuristics
in addition to searching for known virus patterns.
Heuristics are generic algorithms that try to identify malicious behavior by evaluating certain program characteristics
according to their proprietary implementation.
Often it is already sufficient to have a program access the registry or the internet to get this classification. By their very nature
heuristics cannot be exact and frequently lead to false positive detections. Occasionally FreeFileSync is victim of this.
In practice however one can distinguish real malware threats from heuristic alerts: later contain phrases like *gen*, *generic*, *heur*, *heuristic* or *reputation* as part of the threat signature name, for example Trojan.Win32.Generic!BT or Heur.AdvML.B or WS.Reputation.1.
Additionally certain anti virus products will not only warn about viruses but also flag advertisements like the one shown in the standard FreeFileSync installer. The warning dialogs misleadingly use the same layout as would be used for viruses and trojans. In these cases the only way to tell what the AV software is actually complaining about is, again, to look at the threat signature:
If an advertisment is detected, a signature including *PUA* is used, which is short-hand for possibly unwanted application. For example PUA.InstallCore. In other cases a more descriptive term like *adware* is used. These warnings can safely be ignored since the software advertised in the FreeFileSync installer is always optional.
In any case, when in doubt never trust a single anti-virus software and use an online mass virus scanner for comparison.
How can I report bugs or suggest new features?
The best place to get in contact is via the FreeFileSync Forum. This allows for other FreeFileSync users to share their experience and give immediate feedback. A lot of problems have already been discussed and solved, so searching the forum may be the quickest way to get help.
When synchronizing with FreeFileSync and comparing the number of items of the source and target folders with
Windows Explorer, consider the impact of the following settings.
If you still find yourself unable to explain the difference, drill down into specific mismatching folders with both applications until you find an actual file/folder that is handled differently. This should reveal what the problem is.
Copying NTFS permissions is not needed in general and is best left disabled. Go to Menu → tools → options and ensure permission copying is unchecked.
If you are an administrator and really need to preserve DACL, SACL, Owner and Group permissions, make sure the FreeFileSync process is running with admin rights.
Certain anti-virus products, for example
Comodo v8, write hidden alternate data streams
to newly created files.
Unfortunately this has the side effect of also setting the file modification time to the current time.
Since this happens after FreeFileSync has copied the files, the next comparison will detect this modification just like any other external change.
To resolve this problem file a bug report on the anti-virus software's support web site, use a different anti-virus software that does not modify files or look for options to disable such features (e.g. disable Comodo's "File Source Tracking").
This depends on how you have set up deletion handling in synchronization settings:
Usually FreeFileSync will generate a mini dump file automatically when it detects a program crash.
This file can then be sent to the FreeFileSync development team for further analysis.
In some situations this will not work correctly, for example if the process is hanging for a long time rather than crashing directly. In this case you can create a dump file manually as follows:
Download the tool Process Explorer and reproduce the crash/hang. Now start Process Explorer and right-click on FreeFileSync_x64.exe (or *_win32.exe if you're on 32-bit Windows), select Create Dump and then Create Full Dump. Next, compress this file with zip or rar and send it to the email shown in FreeFileSync's about dialog.
If creating the dump file fails with Access denied, check that Process Explorer is running with elevated rights: Menu → File → Show Details for All Processes