FreeFileSync is a folder comparison and synchronization utility. Folders can be added by drag and drop to the UI. The simple UI makes it easy to see the app, just compare two folders and start synchronize. Sync works in one way or two way or you can specify custom syncing. Freefilesync comes with both as installer and a zip archive, the zip archive contains the app, you can use the app with out installing like a portable app. File comparison can be done by either file size and date or bytewise.