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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Average: 4 (144 votes)


I have been a FreeFileSync user for a long time. No more. Synchredible is great. Enough so that I bought the premium version in order to support the developer.

Agreed on FreeFileSync. I'm not going to use a data sync tool that is sharing activity with external servers.
Synchredible looks good but wouldn't backup to a NAS as it won't see it.

I also use a Backup on Save tool. Used FileHamster for years bit its not being updated and uses old .NET. Yardis sort of works but seems to get confused.

As a followup, I've been using Aomei Backupper for imaging my boot drive. Just discovered their version 4 has added Real-time Sync in the scheduling section. This will allow me to use it for Backup on Save functions as well - this is for key files to be automatically backed up with each new version. It avoids loosing a days work if something goes wrong between daily data backups. It's saved my bacon a couple of times.

Synchredible is a good sync tool too though. Cleaner interface than FFS.

G'day David - please explain what you mean by "sharing activity with external servers". What information does it share IYO? With whom? I only sync with partitions on or drives attached to my computer. I don't really see how it is meant to share activity with any one else, particularly as I obviously do not need to be online to sync. I use FFS every day and find it excellent. I even spend a few dollars once or twice per year to support Zenju who has responded well to the few issues I have had, Jon

Hi Jon
The free version of FFS now has ads. That requires sending data to ad servers and returning with the ad content. What that data includes, I don't know but there is often an effort to "target" the ads, meaning they share some user data. I have 0 interest in having adware on my computer, especially when I have no way of knowing what is being shared with who. Many examples illustrate that once that door is opened, collected data tends to expand. There is also issues with opening a door for malware if the unknown ad companies are compromised.

If you've supported FFS, perhaps he gave you a code that turns that off?

I understand why developers are doing this. Its become common for free apps on cell phones and is widespread online. Most people have no clue how much of their user data is being collected and shared unknowingly. But I'd rather not invite that onto my desktop. To use an analogy, it's one thing to have someone listen in on a conversation in a restaurant. It's quite another to have it happen in my living room.

I have been using FreeFileSync for quite sometime now. I haven't seen any ads yet. To confirm, I just opened FreeFileSync, but cannot see ads anywhere in the program.

Are you using current version? I stayed with the old version for awhile to avoid this new "feature" but have now replaced it.

Yes, I am using the latest version.

Then apparently you either paid something (see comment below) or have an exceptional firewall.

Neither. I am using Windows Firewall, and it's the free version of FreeFileSync, and not the donation one.

Curious. That's not been my experience. In any case, I've migrated to a tool I prefer.

Thanks David - yes I did pay something for the new version (9.0) in mid-April, which may explain the lack of adware. The paid version has no ad or crap ware attached. Glad to hear (from others) that Syncredible is good. Will switch to that if FFS gets too intrusive (or expensive), but in the meantime, all my filters and time shifts work well in FFS, and my various backup relativities are saved. It is also remarkably fast - I backup around 100 MB per day to OneDrive - takes 0.5 seconds approx. So for the time being I plan to subscribe every six months or so. Jon

Oh curious. I Googled for the NAS issue and someone mentioning reinstalling Synchredible and then it worked. And indeed it did. I can now sync to my NAS.

Thanks for the recommendation!

FreeFileSync has been updated to version 8.10 (2017.03.11).

I can also vouch for the free version of Synchredible; it truly is incredible and can handle tremendous folder trees without choking as so many of the other programs do.
Many of these programs can handle a few hundred files in a very few folders, but then start making big mistakes the more you throw at them.
I was also able to download and install Synchredible without getting any undesirable hitch-hikers in the process.

FreeFileSync 8.7 has been released (2016.12.06); the full changelog may be found at .

FreeFileSync suits my needs. I find it easy enough to use and it has a pretty simple and intuitive GUi. I've used it on and off for years and always keep coming back to it. I like it so much I donated $20 to the developer.

Unfortunately that payment does not include upgrades. If I do upgrade to any future versions it reverts to the bundleware version, so I'm sticking with version 8.3 indefinitely.

It's a pity they don't just provide a "Pro" version that includes all future upgrades.

Added:- If the pop-up nag to update annoys just add the following two lines to the host file:

Happy update/calling home to mother-ship blocking:)

FreeFileSync is excellent - at least six stars. My MalwareBytes identified OpenCandy as a PUP, but I agreed to install anyway. In practice, no open candy, no malware. But quite why I don't know. As a precaution, I took a registry backup before installing. But this time, and the last two or three, there has been no click-off malware button during the install, and nothing untoward has installed. Actually the program is so useful, that I will go back to donating for each new version - not very much I admit, but I do donate more for major upgrades, eg, when FFS goes to version 9. I am looking forward to the day when Zenju can give OpenCandy the flick and just rely on donations.
Sorry CANCEL THAT - my normal morning MWB scan found:
PUP.Optional.OpenCandy, C:\Users\Admin\AppData\Local\Temp\is-7Q1NL.tmp\OCSetupHlp.dll, , [9d20b1482376ab8ba2b3512123e1ce32]
Encouraging is that it doesn't seem to have done anything, but I have anyway deleted it. I will also post to the FFS forum. I have therefore reduced my FFS rating to 5 stars.

The application Unchecky is quite useful in helping to deal with PUPs (such as OpenCandy) that may be included with an application one would like to install. During the installation process, it helps steer one along the path to the options (if they have been provided) to deselect the PUPs that may have been bundled with the app. It also writes exclusions to the HOSTS file, preventing the PUPs from phoning home ( The app automatically updates itself.

Also extremely useful (in many ways) is the venerable WinPatrol, as another commenter has mentioned (

Both are highly recommended (if not essential) for every Windows box, IMHO.

FreeFileSync has now become a malware site. Unless you make a donation when downloading the program, you will get an anti-virus program installed without any notification or way to opt out, and a search bar. If not for Winpatrol, I would not have know the anti-virus and search bar where being installed. Please stop recommending this software.

It is now common practice for freeware programs to come bundled with unwanted components. This is why we have an installer warning message next to the download link and publish articles such as this.
When you run the installer it is necessary to block any outgoing connections in order to prevent these from downloading additional material although the fact this is happening is clearly stated during the install process.
You can easily make a test install first using one of the freeware programs such as ToolWiz Time Freeze. MC - Site Manager.

I would add a third to this list that gives the other two a run for the money with its free version:

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]