WinDirStat reads the whole directory tree once and then presents it in three useful views:
- The directory list, which resembles the tree view of the Windows Explorer but is sorted by file/subtree size,
- The treemap, which shows the whole contents of the directory tree straight away,
- The extension list, which serves as a legend and shows statistics about the file types.
The graphical representation is clickable, and if you click directory trees, they highlight on the graph as well. The graph showed me that I have a 2 GB text file (shown in the green highlight) in My Documents as well as a 12.2 GB zip file (the largest blue block).