With modern lightweight compression algorithms running at gigabytes per second per core, it's practically a no-brainer to apply them to filesystems to make better use of storage and IO.
CompactGUI AlternativesFile Compressors and other similar apps like CompactGUI
CompactGUI is described as 'Reduce the space taken up by games and programs on disk by using native Windows APIs' and is a File Compressor in the os & utilities category. There are 1 alternatives to CompactGUI for Windows. The best CompactGUI alternative is Compactor, which is both free and Open Source.
Both are front-end GUIs for the Windows utility compact.exe, so they perform the same role. Both have intuitive GUIs, are portable, provide the ability to analyze folders to check for existing compression. CompactGUI pulls ahead a bit with awareness of Steam folders and the ability to estimate compressed size of folders based on other users results online. Compactor has a better breakdown pre-analysis of what is compressible and is a little quicker to navigate around the UI.