How to keep files in sync on multiple devices without Internet storage

The introduction of cloud hosting services such as Dropbox, Microsoft OneDrive or Google Drive have made it fairly easy for computer users to synchronize data between multiple devices.

All that is required is to install and run the sync client on these devices to do so, and even if no client is available, it is always possible to use a web service instead to access files.

While that is great for many purposes, it means that the data is stored on the Internet on servers of the selected company.

Sometimes, this may not be desirable, especially if you only need to sync files in a local area network or if you want to make sure that you retain full control over the data at any point in time.

You can use several programs for this task but one of the easiest to set up and use is Bittorrent Sync.

Note: While data does not flow over the Internet, you still need an Internet connection for connecting to peers. According to Bittorrent, the information is not stored.

Here is what you need to do to synchronize as many files and folders as necessary over a LAN connection.

• Download and install the Bittorrent Sync client on all systems that you want to sync data between.
• Start it up on one system and click the add folder button to add the first folder to it.
• If you want to sync data one-way, select Read Only as the permission and make sure you click on advanced and disable the link expiration option there to avoid that connections are blocked after a set amount of days.
• You may also want to disable the approval option under advanced. If you don't, you need to allow each device connection manually.
• If you want to sync in both directions, switch to read and write instead and follow the one-way instructions from then on.
• Add as many folders as you like this way.

You get a share code for each folder that you add this way which you need to enter on all target machines. You can use a program like Sharemouse or Mouse without borders to copy the code to the other system if they are in reach or use other means to do so.

Once you have added the share key to the Sync client the folder is added.

Bittorrent Sync won't store the data in the cloud and will prefer the fastest route which is using a local area network when possible. If that is not possible for whatever reason, it may sync the data over the Internet instead but again without storing it on third-party servers to do so.

Alternative: Microsoft SyncToy

Synctoy can be used to pair folders between different devices. Note that you can only create folder pairs between two devices which makes it less of a solution for situations where data needs to be shared between more than two devices.

Alternative 2: AeroFS

The free limited version of the program is good for a maximum of three users. The program itself is cloud managed but does not store data in the cloud. This means that you need an Internet connection for that.

Alternative 3: SparkleShare

SparkleShare is a server product that you can install on a computer that works as a local file synchronization server. It is used by devices that you connect to it to sync the data. The downside here is that you need to set the server up which can be quite the daunting task for inexperienced users.