FreeFileSync is a free open source folder comparison and synchronization tool. One of my big problems is keeping track of photos on my external drive/s and this puppy is just the thing to help me weed out duplicates and recover wasted space. The synchronize function is also great for keeping off-site copies of your folders/files, although it pays to be extra cautious how you use this if you’re dealing with crucial files.
FreeFileSync is an Open-Source folder comparison and synchronization tool. It is used for fast and easy configurable sync operations between two folders without restricted or overloaded UI interfaces.