FolderSizes is capable of comparing file system data currently in memory (which can be visualized through the Scan Data Panel) with scan data loaded from XML.
Comparing current file system analysis data with previous data effectively "subtracts" loaded data from the existing file system nodes in memory (more on how this is shown in a second).
To compare file system analysis results, follow these steps:
1.Perform an initial file system analysis and save the resulting scan data as XML.
2.At some point in the future, perform a file system analysis of the same root path(s) as step 1.
3.Now use the Compare button in the application ribbon bar to open the XML data file saved in step 1.
Once this process is completed, the user interface will automatically reveal the Scan Data Panel (if it's not already visible). The Scan Data Panel provides a hierarchical, differential view of each file system node in memory compared against that loaded from XML. It will also provide simple color coding to designate folders that have grown in size (shown in red) vs those for which the size has been reduced (shown in green).
When viewing file system nodes that in comparison mode, the primary detail view will also reveal differential file system object metrics.
To take the Scan Data Panel out of "comparison mode", you can remove the file system nodes currently being compared (through the Scan Data Panel toolbar) or refresh any of the nodes within the comparative hierarchy.