DiskSorter classifies files using a number of built-in file classification plug-ins capable of recognizing more than 3,500 types of files. The default file classification plug-in categorizes files into a logical hierarchy of file types sorted by the amount of disk space per file category. In order to change the file classification plug-in used for a file classification operation, open the file classification profile dialog, click on the file classification plug-ins combo box and select an appropriate file classification plug-in.

DiskSorter performs file classification operations, shows the file classification results and saves the file classification reports according to the file categories defined in the selected file classification plug-in. The default file classification plug-in shows a hierarchy of file categories and file types sorted by the amount of the used disk space. For each file category, DiskSorter displays the number of files, the amount of the disk space and the disk space percentage.

The extension-based file classification plug-in builds a hierarchy of file extensions and shows the used disk space and the number of file for each file extension. All file classification reports will show a list of file extensions and file management operations will be performed on one or more selected file extensions.

Another useful file classification plug-in is the modification date file classification plug-in, which builds a hierarchy of modification dates and shows the amount of disk space and the number of files that were last modified during each specific period of time. For date-based file classification plug-ins, file classification reports will show periods of time and file management operations will be performed on files that were last modified during a specific period of time.

IT and storage administrators may be interested to display the amount of used disk space and the number of files per user or per user group, which may be done using the user-based and group-based file classification plug-ins. The user-based file classification plug-in builds a hierarchy of user names and shows the amount of disk space and the number of files per user. The group-based file classification plug-in builds a hierarchy of user groups and shows the amount of disk space and the number of files per group.

Another option is to use the permissions-based file classification plug-in, which classifies all files by the NTFS ACL permissions and shows the number of files and the amount of the disk space for each file system permission type.

Moreover, the second-level file filters provide the ability to show the disk space usage and the number of files per user for a specific type of files or a file extension. For example, classify files using the user-based file classification plug-in, select the 'Classify By Extension' second-level file filter and click on a file extension to display the amount of disk space and the number of files per user for the selected file extension.