Using the Directory Comparison view, you can compare two similar file folders and see which files and directories differ and which are the same. 


As the comparison runs, the view will populate with compared files and folders. Each file or folder will either be marked with a dot or nothing at all.



For each changed or single file, Changes will attempt to deduce which file is newer by using each file's timestamp. If the file on the left is newer than the file on the right, an arrow pointing from left to right will appear in the center of the row. If the file on the right is newer than the file on the left, an arrow pointing from right to left will appear. You can double-click on these arrows to change their direction or to tell Changes not to merge the files at all. These commands are also accessible via the Merge menu and the Merge from Left, Merge from Right, and Do Not Merge toolbar buttons or the Merge menu.


When you have completed your scan of the Changes suggested merge directions, use the Merge Commit… command to sync the folders.


You can save your directory comparison settings for later use if you wish via the File Save menu item.


Double-clicking on a row or pressing the Return or Enter keys in the Directory Comparison window will cause Changes to attempt to run a File Comparison against the two files in the row. If the files are incompatible with the File Comparison tool, the comparison will not be launched. Right click on any row for a context menu of actions including Open With Finder… and Open with Quicklook….


Learn more about: Excluding Files from the Comparison, Changing Filter Selections (Directory Comparison)