Dropbox is the most widely used and simplest file-synchronization system worldwide not attached to a major technology company. Every machine on which you install Dropbox and use the same account has ...

It is probably the first thing you need to check if you are getting synchronization issues with Dropbox. For obvious reasons, Dropbox requires a valid internet connection to synchronize files.

Replacing Dropbox with Syncthing, for most users, will feel like a drop-in replacement as long as you know exactly what you're looking for in a tool.