Like many people I take quite a few photos, and also like quite a few people I don't back up as frequently as I should.

What I'd like to be able to do is automatically synchronize my "to be backed up" folder to some of the other machines that live on my home network.

I need something that:

  • Doesn't require anyone to be logged on
  • Monitors folders and doesn't require a manual start
  • Only sends across what has changed
  • Doesn't force traffic over an Internet connection (The initial sync may be several gigabytes)
  • Isn't limited beyond local available disk space (EDIT: For the sake of argument, assume there is in excess of 50 Gb that I'd like to float around.)
  • Copes if "the other end" goes away unexpectedly, is not available (for instance, If I've taken my laptop to see my parents, I obviously won't be able to see my desktop PC)

Is anyone aware of anything that fits the bill? I've come close, with things like Windows Live Mesh (but that is both limited in quantity, and requires me to be logged on at both ends for the sync to er, sync), but I want to evaluate the options before sitting down and developing something myself if needs be.

Does anyone know of anything that fits my requirements?

  • Just emboldened the more important points. For the sake of completeness, one system that handles almost all the points is shared folders in MSN Messenger (obviously falls foul of the requirement to work without being logged on) Jul 15, 2009 at 12:34
  • do you require internet and lan or just lan?
    – Josh
    Jul 15, 2009 at 12:36
  • 2
    I only need LAN (I already have an Internet based backup solution for other important files provided by my ISP). Jul 15, 2009 at 13:32

12 Answers 12


You're asking for a lot.

Since internet syncing is out, you can't go Dropbox which is what I would have voted for.

You could take a look at SyncToy, since from your tagging I'm assuming you are on Windows. It is free from Microsoft.

However, this MAY not fulfill your demand of "not being logged on". I am not quite sure how to interpret this. SyncToy does not work when you are not logged on on the machine that requires a sync. However, it can pull data form unattended machines (as long as these give access to the protocols that SyncToy uses.

SyncToy has worked for me and for my friends in the past. I am not currently using it, because I switched to a Mac.

Update: from Windows users, I also hear good stories about SyncBack, which offers a free version.

  • I'll look into this further, I didn't appreciate it could sync with an unattended host -- I'm happy with a requirement of being logged on at least on the host generating the files. Jul 15, 2009 at 15:54
  • I'd forgotten all about synctoy. You can set up a scheduled task on it so you don't need to be logged on, it will only copy files that have changed. The only thing it won't do is be continuous Jul 15, 2009 at 19:17
  • Theoretically, once the initial sync is done, I could set up a scheduled task to run every hour to do it, making this the closest match to my requirements. Jul 15, 2009 at 19:52
  • 3
    Added SyncBack as a possible solution.
    – dyve
    Jul 19, 2009 at 6:55
  • +1 for Syncback, the free version works fine. It can be set-up to run periodically as a windows task and does not require someone to be logged in.
    – Angelo
    Dec 7, 2012 at 14:17

The options from Microsoft are Windows Live Foldershare and Live Mesh. Both are under development.

I used to use foldershare and found it quite snappy and reliable.

I currently use Live Mesh. It (currently) offers 5gb of cloud storage, and I use it day to day between 4 computers. It also allows you to remote desktop between computers through firewalls, and sharing folders with other users of the service.

To answer your points though, with Live Mesh:

  • You need to be logged on
  • Monitors folders
  • Only copies changes
  • Uses local connections when possible
  • Doesn't care if there's no machine on the other end. Can use cloud storage at the same time
  • Documentation prior to installation is a little bare on Windows Live Foldershare - I've evaluated Mesh before and found it a little slow for my needs. Jul 15, 2009 at 19:50
  • 1
    It's Windows Live Sync: sync.live.com Jul 27, 2009 at 23:44
  • Windows Live Mesh used to be good at this, but they've killed that direct PC-to-PC feature. So we're back to square one... sigh...
    – RomanSt
    Apr 24, 2012 at 13:57
  • Also, when Windows Live Mesh is active, forget about using your PC. It has no Pause feature and no way to throttle neither its CPU usage nor the bandwidth. It even fails to set itself as Idle priority, which is an absolute must for a CPU-heavy background process...
    – RomanSt
    Jul 7, 2012 at 13:00
  • With Windows Live Essentials 2012, Live Mesh has been deleted. The live mesh installer enables installing mesh nevertheless.
    – koppor
    Dec 6, 2012 at 21:05

SyncBack is so good it deserves its own answer :)

I think it meets all your requirements. Almost. I'm not only sure if it fits Isn't limited beyond local available disk space. What do you mean by this?

  • By that, I mean that it's not capped to only sync (say) something small like 20Gb Jul 29, 2009 at 13:38


  • 4
    -1: DropBox forces everything over an internet connection. Quote "Doesn't force traffic over an Internet connection (The initial sync may be several gigabytes)" I know I pay for bandwidth by the Gigabyte - it't not pricy, but I'd not like to expend 100GB+ of bandwidth (and how long in time?) for something I can do by wire in an afternoon.
    – Bevan
    Jul 19, 2009 at 10:47
  • @Bevan, This isn't the case anymore, DropBox can sync over LAN where possible. The problem is the original question mentions not wanting to actually sync onto anything cloud and instead only sync locally, which DropBox does not provide. Feb 20, 2012 at 22:45

I've just remembered ViceVersa

I use it to sync my local development code with my virtual server so I don't have to keep publishing. It runs on a single PC and can monitor multiple folders and syncs them when it detects a change or on a schedule.

  • It can run as a service so no one needs to be logged in.
  • It monitors the folders for changes
  • It only syncs the new files
  • It runs on the LAN
  • The Pro version can sync opened files (such as Outlook.pst)

I would install it on the Desktop PC so that it runs whether the Laptop is there or not.

It does cost but there is a free 30 trial.

  • +1: This looks like it could do it, but Windows SyncToy has a better price point ;) Jul 15, 2009 at 19:55

Fairly new on the market (as in it's still in Alpha) is BTSync. It ticks a surprising number of the items on your list and is still under development so more items could well be sorted.

  • The ability to run BTSync as a service is something that is under development.
  • Automatically checks the directories for changes
  • Chunks the file into 4mb sections and only sends across those that have changed (although this algorithm needs some improvement as it doesn't do a differential copy)
  • Uses LAN transfer whenever possible. Only goes via Internet if it needs to and also supports using relay servers if a direct connection isn't possible.
  • Doesn't actually support cloud storage so only limited by your disk (although memory usage is high for a large number of files currently).
  • Copes with handling changes in folders happening offline. Doesn't merge files automatically.

It also supports a bittorrent-style method of distribution, so adding a new node will download from all of the existing nodes, and supports having read-only shares, so that a true-backup style solution can be created.

  • Link is down. Haven't found a working new one.
    – nixda
    Jul 25, 2013 at 9:50
  • Hi @nixda, both of those links are still working fine here Jul 25, 2013 at 14:31
  • It says "The requested URL could not be retrieved". Maybe its an issue on my side. Strange. Nevermind.
    – nixda
    Jul 25, 2013 at 14:36
  • Try using the Coral Cache version of the links: labs.bittorrent.com.nyud.net/experiments/sync.html and forum.bittorrent.com.nyud.net/topic/… Jul 25, 2013 at 15:22
  • BTSync as of 2014/06 is still in beta but now works conveniently with your camera like devices like tablets and smart phones as well as your Windows clients and Windows Share NAS. The downsides are that it isn't vetted in a open-source manner, you cannot specify local LAN only, and that you cannot enforce shares to be truly non-public. (What if somebody correctly guesses your share key? Very very very low possibility but still.)
    – piyo
    Jun 1, 2014 at 3:56

I would like to propose a new opensource tool called Syncthing, which is very simple to setup and works over any connection setup (wifi, ethernet, LAN, WAN/Internet) and devices (from computers to smartphones).

I tried it to synchronize my smartphones and my home computer over Wifi, plus my home computer with my work computer over internet, and this all worked nicely.

The only drawback is that both devices you want to synchronize must be turned on during the synchronization, but this is also an advantage because this is due to the fact that there is no middle-man server like Dropbox (no eavesdropping).

  • This is definitely the way forwards. Have been using this personally for a while now Jul 18, 2017 at 9:49
  • Yes and it is very easy to setup, that's pretty impressive when you know the complexity of the technology necessary to achieve peer2peer encrypted synchronization. An alternative is to use SpiderOak's SpiderHive, since it's zero-knowledge encrypted it's also a good choice, but you can do the same at home by using Syncthing, you just need to have one device always connected to internet to receive the data from any device and propagate to all the others.
    – gaborous
    Jul 20, 2017 at 15:29

I use an app called GBridge for a couple things. It creates a VPN and allows local access to PC's even if they're not on the LAN.

I use it for Remove Desktop (well... VNC) from just about anywhere and I have shared folders that auto-sync (on a schedule)

The only downside is that the whole program is a little rough around the edges sometimes..but free apps often are.

I like that it's not server based at all, it just uses google's authentication system not for file transfers.

Data will remain on the LAN if the machines are both local, and use the internet only if needed.

I think the only way GBridge fails to meet your qualifications is that I'm not sure about the login requirements.

  • Looks like this needs to be interactively logged on in both places, which is a deal breaker for me. Jul 15, 2009 at 19:53
  • According to a forum entry, it does not allow copying opened files.
    – koppor
    Dec 7, 2012 at 12:06

Another very good alternative is Sugar Sync, with a free 5GB account.

Sugar Sync is really efficient with transferring large files between computers. I have tried the other alternatives as well but this one is the best among them.


i use DropBox

it creates a special folder in your documents folder which you can save directly to. it will then sync online and to other computers setup with the same account.

you can set it up to start on startup and it remembers your login details so you don't need to re-enter them each time.

There is a free version which is 2GB.

I'm not sure about the other requirements but it is definitely easy to use and also has the bonus of a public folder that you can use to share files publicly.

Hope that helps,


  • 4
    He asked for a solution that "Doesn't force all traffic over an Internet connection". From what you've said, DropBox doesn't meet this criteria...
    – x3ja
    Jul 15, 2009 at 9:14
  • The "doesn't require anyone to be logged on" is a key requirement (different members of the household could be logged on to different hosts at the same time), as is the "don't force traffic over an internet connection", as I generate more data than my bandwidth cap would allow me to up/download Jul 15, 2009 at 9:18
  • 1
    Good point - they are looking to add it forums.getdropbox.com/topic.php?id=39&replies=8#post-147. As I said in my answer I wasn't ticking all the boxes but I thought it might be helpful.
    – Josh
    Jul 15, 2009 at 9:23
  • 1
    Posting referral links that aren't disclosed as such is a little sneaky, don't you think? It verges on being spam, as it doesn't solve the problem described, but you get something out of people finding the link through here. Jul 15, 2009 at 9:24
  • 2
    removed referral link - sorry wasn't trying to be sneaky.
    – Josh
    Jul 15, 2009 at 10:45

Haven't researched this very much at all, but use Jungle Disk for our digital images. Both as an off-site (cloudbased) backup of them, and as a way of accessing them from multiple machines: just set a large local cache and photos you accessed earlier will be on your local disk.


A small Network Attached Storage device (NAS) with four identical disks (for RAID 5) would seem to be your ideal solution. A NAS is essentially a small low-powered server dedicated to serving disk shares. Multiple clients can use the shares at once. Synchronisation happens as quickly as the clients' operating systems allow.

  • A NAS doesn't require anyone to be logged in.
  • It is available continuously, thus doesn't require a manual start, and with RAID 5 you get some resilience against hardware failure.
  • Delta compression really depends on the application you're using. I expect it's possible since a NAS just presents as a disk.
  • Only uses an internal network connection, not Internet.
  • No limitations beyond disk space.
  • If you take your laptop to ma's, the operating system should cope just fine after the initial "Whuh? Where'd my disk go?" shock. In my experience, it takes Windows a little longer to calm down than Linux.

It's not especially cheap:

1 x NAS @ £146.88 = £146.88

4 x 4TB NAS drive £199.99 = £799.96

That's nearly £1000 all told.

But with RAID 5 that gives you 3 x 4TB = 12TB of disk space, which I guess should keep you going for a while?

  • I already have a NAS - my issue is automatically copying files to it (or another PC which is always connected, and can sync to the NAS on behalf of the laptops), when reconnecting to the network. Dec 31, 2015 at 10:27
  • Good. We're halfway there already. All that remains is to find a suitable backup tool. I see from your original post you use Windows. My first thought is to use a batch script on login, but that doesn't fit requirement #1. May I ask the reasoning behind requirement #1 ("doesn't require anyone to be logged on")? Dec 31, 2015 at 11:01
  • That requirement is based on the issue that the laptops might be used by a different user (wife, son, etc.), who might not have permissions to the folders I want to backup Dec 31, 2015 at 11:08
  • This answer stackoverflow.com/questions/4437701/… seems to indicate that a script can be run logged off by Task Scheduler. I was thinking of using Task Scheduler anyway, but it might be onerous to run the script as often as you'd like, seeing as you're dealing with many small files. My naive approach is to run through all the photos, pick out the ones without the 'archive' flag set, copy them over and then set the 'archive' flag. A more sophisticated approach might make use of a small SQLite database as a catalog of backed up photos. Dec 31, 2015 at 11:35
  • Currently, I manually, periodically use robocopy, when I know the remote server is available - this handles the "stuff that's changed", "not via Internet" and "no quota" requirements, but less so coping if the network is interrupted/not connected, nor running unattended. Dec 31, 2015 at 11:53

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