What software exists that can sync between two Windows PCs over LAN?

Question

What software exists that can sync a specific directory between two Windows PCs over LAN and LAN only (i.e no cloud access requirements like dropbox)?

Features I am looking for:

• Easy setup (GUI tools preferred)
• Does not require external sync servers or internet access
• Optionally support for other platforms

Answer 1

MS SyncToy has long been a favourite synchronization option of mine.

• It is free
• Setup is very easy
• It only runs on Windows but it can sync between any folders that you can access via Windows Explorer (ie mapped network drives, my network, USB Drives).
• Quite simple GUI - but if you can set a fair bit of advanced options like skipping hidden or read-only files or checking file contents as well as default of just timestamps, or skipping some sub-folders.

You can have effectively unlimited sync pairs (ie if there is a limit it is well over 200) Each sync pair is two folders that it compares; they don't even have to be on the computer that is running SyncToy.

About once every 18 months - 2 years one of my regular major sync operations (there are 8 of them that I run 2x weekly that are checking well over 20k files each - up to 60k files) gets corrupted and forgets what the heck it is supposed to do; as it does preview this isn't a serious problem - you're likely to notice when it thinks it should be doing 20-60k operations suddenly. When that happens you just delete the folder pair and recreate a new folder pair; sometimes this does mean you have to use preview to manually merge changes (because after doing that it has no history so renamed files can be duplicated otherwise).

Answer 2

Windows has this option built in already.

Following the instructions on that link will set up almost any directory on your PC and will allow it to be shared with any PC on your LAN, regardless of OS. In fact, once you set it up, you can access that folder from PC, Mac, iOS, Android, XBox360/One, PS3/4, and more.

If you are looking for something different than this, can you provide more details?

Windows has a file synchronization system built in as well, that, in my experience seems to work a bit more like Dropbox than simply sharing a folder. See this page for details.

Also, here is a LifeHacker Article that may help as well.

Answer 3

Bittorrent Sync (wikipedia) seems to fit rather well. It automatically syncs files between devices whenever connection is available, handles collisions if those happen, and is compatible with Windows and others. It does not require central server (or specific laptop) to be available.

On the negative side, it's still beta, and might be discontinued. However, recent news says that its userbase is already over 2M, so discontinuation is probably not the biggest risk.

My experience so far:

• Performance over LAN/wifi is good. Easily, but for gigabytes transfers it saturates the network, difficult to use the Internet until transfer is finished. There are options to limit both upload and download rates, but they were not working when I tried them, traffic kept using all available bandwidth.
• Clocks must be synced (relatively well, +-5min is tolerable), otherwise Sync refuses to work.
• Setting up shared folders is easy, but there's no way to exclude some of the contents (for example, temp files).