Best Free Folder Synchronization Utility



File synchronization utilities help you keep updated copies of files or folders in two or more locations, such as different computers, network drives, USB drives, or online storage. While a file sync utility could be used as a simple backup tool (called one-way syncing), its real power lies in keeping an identical set of working files in two or more locations.

An example of this would be keeping current versions of the same data files on both your home computer and office computer (two-way syncing). File sync utilities keep track of which files you create or change, or even delete in one location, and can create, change and delete those same files in the other location.

There are a lot of contenders in this category, but only a few stand out based on the criteria below.

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Rated Products


A well designed and easy-to-use sync program

Our Rating: 
License: Free (Open source)
Very easy to understand and use "straight out of the box."
Very few filter options, no ftp, no auto sync, very sparse help.
Read full review...

Allway Sync  

A very well rounded product with a filter, rule set and loads of features

Our Rating: 
License: Free (Limited features)
Very robust set of filters and rules, support for FTP.
Monthly file copy limit of 40,000 files, no support for copying locked files.
Read full review...

Honourable Mentions

  • SyncBack supports file compression and can verify file integrity after job completion.
  • Synkron had a lot of votes for this one in the comments section.
  • File Synchronizer is good if you are looking for a minimalistic or simplistic utility.


Related Products and Links

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This software review is copy-edited by Ian Richards. Please help edit and improve this article by clicking here.

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Though only garnering an Honorable Mention, SyncBack Free has been updated to version (2016.03.16); VirusTotal reports it to be 100% clean.

FreeFileSync has been updated to version 8.0 (2016.03.15). (The Windows executable downloaded from the developer's site [] received three detections for OpenCandy by VirusTotal.)

According to, "All versions of FreeFileSync after 6.2 are broken and can't be run from other apps. This prevents packaging, use of the base portable version with the PA.c Platform, use of the local version with a scheduler, use of the local version with an alternative start menu, etc. Details are in this bug report from March 7, 2014" ( VirusTotal scans version 6.2 as clean.

Allway Sync 'n' Go is my personal choice for a file/folder synchronization utility. Pluses are it runs portably, it has plenty of customizations to sync jobs, runs automatically in the background or on a scheduled basis, has a pleasing GUI, was easy to learn without use of help files, and I have had none of the problems talked about in the comments for this article.

Though I don't use FreeFileSync I have tried out the installer and portable versions obtained from the developer at and am pleased to say that in version 7.8 there are no bundled pups or use of open candy. The links in the article should be changed as the sourceforge download link only downloads a text file saying to go to the developer's site for the real download.

I'm a tech and tried alwayssync'ngo the portable always sync, it loaded on the wrong drive choose my data drive d instead of my external drive and thats where the trouble started It altered the names of my drive to sync c and sync d it changes the system ini file and core files . I finally loaded it to the external drive and didn't like it so big mistake I removed it External drive now dead I'm a light tech I have lots of recovery tools force defrag etc nothing worked I use acronis true image which seams to effect this program . I tried using another computer to fix the damaged external drive and corrupted that computer as well
So if you install sync'ngo to an external drive and don't want it just leave it there never remove it . Bob Forrest

"... WinDataReflector is a lightweight file synchronization and backup tool that wraps up fast file comparison and transfer algorithms into a simple and clear interface that offers you visual comparison of files and folders before synchronizing and backing them up and support for two way synchronization with fully customizable rules ...":

I've tried FreeFileSync and it works well. Easy to uncheck the extras during install if you're careful. I used it to replace the abandoned MS SyncToy.

One gotcha - Save your sync folders before you run a sync or it drops them when done.

It now also includes a second tool called RealTimeSync - this checks at the set interval for changes in a folder and if it picks up on something, it runs a quick sync. A few keys though - you have to set the watched set in FFS first, as a batch file to avoid the gui. And then you have to set a command line in the new tool to FFS and the batch file. And then you have to actually start the program to have it running. You can set a shortcut into Windows Startup but it's a little cludgy as yet.

[edit: commercial reference removed as the vendor no longer provides a free version]

Like many other freeware nowadays, FreeFileSync comes bundled with OpenCandy since a long time now. It shows the bundled software during installation, which can be easily opted out, if you are careful enough. I have been using FreeFileSync since a long time now, and never had any problem.
FreeFileSync contains unwanted components as is made clear in both the review text and product details. MC - Site Manager.

Non-geek as i am, it's not easy to understand all the "warning signs"!

So, if i ignore all the various dubious things it wants to install, i'm safe?

Staying "safe" is not just a one stop ride. It requires users to develop a safety first state of mind when surfing the web and installing programs. Unfortunately, very few are prepared to do this and then complain to us when they get burned. Others rely on their antivirus for protection because the ad on the vendors site promises to do just that and they too often end up in the same state. If you take the time to read the advisory article linked from the review page, it will guide you towards an appropriate strategy, including the use of virtualization software so you can test out new programs without risking the contents on a live system until you are certain nothing malicious is present. MC - Site Manager.

I tried Allway Sync a few years ago and found that it strewed database files all over my hard disk. As a means of keeping track of files in each folder and helping to manage collisions etc it creates a database of all the files, dates etc and stores this database file in each folder.

At the time I decided I didn't want that so I didn't use the software. I am interested to know if it still works in this way.

When I installed FFS 6.12 a few days ago, a large screen offered to install myPCbackup. Very obvious and easy to click off. Sorry SourceForge won't allow me to post a screenshot. No-one can object to that type of splash screen. If all the OpenCandy offerings were as obvious as that, FFS would not merit a single complaint over malware installation.

I downloaded from Fosshub, since both for 6.12 and 6.11, on my system, the SF download link would not work, either in Firefox or IE. Not sure what can be blocking it. Ideas welcome.

I've just installed FFS 6.13 and I'm happy to report that no additional software was offered or installed. Great!

Update Feb. 2015: Another download and install. Sadly the "additional software offer" is back. In this case I had to click "Advanced Options" to then uncheck the installation of the unwanted software. How sad :-((

As far as I can tell, the latest FreeFileSync (6.12) has dropped Open Candy and now just offers to install Opera.

Beware FreeFileSync!!! Still loads malware. I declined additional software at installation but it still loaded different files - Smartbar, Vosteram, Getnow, Snapdo, Quickshare, changed all browser settings and registry. Took several reboots to finally clean up. Not tested FreeFileSync yet. It may be "free" but comes at a price and a mega nuisance to clean up!!!

Just installed the new version of FreeFileSync, version 6.12, released today. Have been using and installing FreeFileSync for a long time now. Never been infected, including today. There was an option to opt-out of the bundled software. Yes, they have changed the screen for that a bit, which I will have to test more. However, I was able to opt-out of the bundled software without problems. No extra software/malware installed on my system, like always. If you are careful enough, the extra software can be avoided easily.

I saw your comment after posting above.

I just ran the installer (portable version) and got no notification (from Comodo CIS) of Open Candy trying to connect to the web.

I also unpacked the installer and found no OC dll inside and lastly checked the installer with MBAM which reported no PUPs. (The Freefilesync installer was always picked up by MBAM previously.)

The installer and the portable version are both included in an installer version. While installing, it asks you which version you want to install it as. I use the installer version, so cannot say about the portable version, as I have never installed it. If no adware is in that, that's good. However, I can say for sure that adware is indeed included in the installer version. Now, whether it's OC or not, I don't know. But, bundleware is there definitely.
I'm also thinking that our desire to be specific regarding OC, tool bar types and other stuff isn't perhaps as helpful as we would like it to be. Developers are very smart. They stuff with one product and then change when the flak for it gets too heavy. They also vary the way in which the opt-in and/or opt-out items are presented during the install process. Having specified the nature of the bundle in our review(s), it then becomes quite a challenge to keep up with these changes. I'm more leaning towards a general advisory stating that a product is, or has been, bundled with PUP's and that users should take extra care during the installation. A general warning about all freeware products is a valid argument but IMO too much of a cop-out. Certain products though do have a history with grey additions and it is right that we highlight these in our reviews. MC - Site Manager.
I definitely agree with what you wrote MC, and also the approach.

Yes :-)

I was only posting to the effect that FreeFileSync seem to have ended their relationship with Open Candy, which makes the review in this article somewhat misleading. Unless OC themselves have changed the way that they operate, which is something I need to look into properly.

Unpacking the FreeFileSync installer exec shows that OCSetupHlp.dll is not included in this release, along with the other indicators that I mentioned, so I'm reasonably confident in saying that OC isn't bundled with this version.

I didn't intend for a moment though to suggest though that FreeFileSync no longer bundles offers with their installer.

I think MC has a very good point ... even if OC has (apparently) been dumped with respect to v6.12 of FreeFileSync, that's no guarantee that it won't be back in v6.13. Or indeed that OC themselves haven't changed the way they work. As MC says, keeping up with such changes would be a time-consuming activity and even impossible if vendors are looking at ways of tricking users who know how to look for, and avoid, bundling such as Open Candy.

Conversely, inaccurately stating that FreeFileSync bundles Open Candy is imv something that might possibly impact negatively on this excellent website. So perhaps a less specific warning to users is a better way forward? A "more general advisory" could warn users against those vendors who practise bundling while avoiding the need to update articles with every release of a software version, except perhaps in the case of important changes.

Curiously though I did run the "normal" (i.e. non-portable) installation just now (CIS sandboxed) and it gave me no offers at all, which has given me pause for thought as to whether the installer has registered my previous selections. I don't think it can have as I "approve" each registry edit on a case-by-case basis, but I'll have to investigate this in more detail later.

Lastly, I'm at a loss as regards previous posters. I've used the SourceForge installer since FFS moved there and have never experienced anything like that described re; the "crapware" that's mentioned, even on a raw and unprotected O/S. I've never found FreeFileSync to install anything that I didn't want, as long as I pay attention during the install process. I do know though that some alternative download sites are somewhat less than transparent, so I wonder if these comments come from people who get the software from other sites.

It's a difficult call ... I mean FreeFileSync is undoubtedly the best in its class imo and I can hardly blame them if they want to make some income from it.

Bundling seems to be a fact of life these days with a lot of freeware, and personally I don't have any problem with it. As long as people stick to well-known and reputable sites and practise "safe computing" - i.e. system back-ups (especially drive imaging - and careful installations etc - then I don't think we really have a lot to worry about for now.

Thanks for the explanation :). I agree that if FreeFileSync is not being bundled with OC, then we should update the article. But, yes, that also means that we have to be sure that FreeFileSync is not being bundled with OC. As you say, they might not be bundling OC anymore, or, OC might have changed how they work... don't know. Looking at this, MC's approach seems more logical, to just generically give a warning rather than a specific one. Also, when an article does not have an editor, like this one, the updating of the information too is difficult. With reviews maintained by editors, they take care of the updating, but with such reviews, it's difficult to update the information. You are right, bundling software with freeware is increasingly becoming a trend, but yes, unless an opt-out is provided, I do not have any problem. I too did not have any problem with FreeFileSync till now, of having unwanted software on my computer. I guess that either the users who are complaining downloaded the software from some other place, or, the likely possibility is that they were somehow not entirely careful during the install process. Cannot blame them fully, because the software vendors keep changing tactics on the opt-out screens, to make the opt-out process really tricky, to lure users. Have to be really careful.
Have now amended the wording of the cautionary notice. MC - Site Manager.

Yes, it is sad that FFS feels it has to bundle crapware, as the program itself is six star (IMO). Apart from clicking off the installer, my solution to the risk is to take a restore point before installing to be able to remove unwanted software and register entries if necessary. Malwarebytes may also be effective in preventing installation.

FreeFileSync is bundled with Malware!

For FFS there exist two "installers":
This one: (11.1) MB
and this one:

The latter is not the 11.1 MB installer, but some 773 KB helper program. This helper program installs - if you are not very careful and read the fine print - Optimizer Pro and other things. It also downloads the 11.1 MB "real" installer.

Late one night I didn't pay attention and accidentally installed Optimizer Pro and two other unwanted items, one of which was Astromenda, a browser hijacker. It placed itself in about 170 registry entries and was a real pain to remove.

So FFS is great software, but the bundling with malware is unethical.

Thanks for the link. I used the fosshub link. It warned to watch for extras. For 6.14 it asked for approval for Tune utilities i also saw with something else. Nothing else installed.

I notice it now also comes with a Realtime Sync tool. Thats great - this can cover 2 tools I used to use.

FFS WatchOut!
an update FreeFileSync is now OFF my machine for good - installed FFS 4.11 today (from SourceForge source) hoping it would fix 4.10. Again being careful to uncheck any boxes as I installed. This time it installed without error but the program fails to sync with any folders or do the job I need it too. It has also hijacked my browsers with some rubbish called Lasaoren and installed some other rubbish called PC Optimser. FFS and Optismer Programs easy to remove, Lasaoren is proving harder

I think you meant 6.11, since that's the latest version which became available for download today. I installed FreeFileSync 6.11 on my computer today, and it installed without problems. I was successfully able to avoid the bundled extra that was shown during installation. No extras or unwanted program were installed on my computer. And I just synced a pen drive containing my software collection with the one on the computer, and again, I had no problems. So, seems that the problem is local to you. Have you tried uninstalling the software completely, and reinstalling? While installation, were you careful to avoid the extra software that is offered? It's easy to opt out of.