Dropbox, by default, syncs everything to all of your computers. But maybe that’s not what you want.
If you have Dropbox installed on multiple computers, or share an account with family members, there might be folders synced to the service that you don’t want on all of your machines—especially if you’re low on hard drive space.
Happily, Dropbox lets you choose which folders sync to which computers. It’s called Selective Sync, but to find it you’ll have to dig a little bit.
First, find the Dropbox icon in your system tray. On Windows there’s a good chance that you’ll need to click the up arrow to the left of your system tray, in order to see the rarely-clicked icons. On a Mac, this will be in your menu bar.
Whatever your operating system, you’ll see the standard Dropbox window, which includes a rolling list of recently synced files. Click the gear icon, then click “Preferences”.
A window will pop up. Click the “Account” tab in this window and press the button labeled “Selective Sync”.
From here, a sub-window will pop up, allowing you to uncheck specific folders or sub-folders. Uncheck anything that you don’t want synced to the computer that you’re currently using. I share an account with my wife, so I could for example uncheck her work folder.
Note that unchecking a folder will not delete that folder from the cloud or any other computer: all this does is prevent the given folder from syncing to the computer you’re currently using. If there are files you don’t want on other computers, you’ll have to repeat this process on those machines.
Once you’ve chosen which folders not to sync, click “Update.” Dropbox will ask you to confirm your decision, explaining what it means.
Dropbox will then get to work on deleting the files you unchecked, and will not sync them to this computer until you change the setting back. As mentioned earlier, the files will remain available on the web and on any other computers you’ve set up with your Dropbox account.