ncdu is described as «A disk usage analyzer with an ncurses interface, aimed to be run on a remote server where you don»t have an entire gaphical setup, but have to do with a simple SSH connection» and is a very popular disk usage analyzer in the os & utilities category. There are more than 25 alternatives to ncdu for a variety of platforms, including Windows, Mac, Linux, BSD and KDE. The best alternative is WinDirStat, which is both free and Open Source. Other great apps like ncdu are WizTree, TreeSize, Baobab Disk Usage Analyzer and DiskUsage.ncdu alternatives are mainly Disk Usage Analyzers but may also be System Cleaners. Filter by these if you want a narrower list of alternatives or looking for a specific functionality of ncdu.