ncdu (NCurses Disk Usage) is a disk utility for Linux systems. Its name refers to its similar purpose to the du utility, but ncdu uses a TUI under the [n]curses programming library.[1] Users can navigate the list using the arrow keys and delete files that are taking up too much space by pressing the 'd' key. Version 1.09 and later can export the file listing in JSON format.

ncdu was developed by Yoran Heling to learn C and to serve as a disk usage analyzer on remote systems over ssh.

Ncdu is a disk usage analyzer with an ncurses interface. It is designed to find space hogs on a remote server where you don't have an entire gaphical setup available, but it is a useful tool even on regular desktop systems. Ncdu aims to be fast, simple and easy to use, and should be able to run in any minimal POSIX-like environment with ncurses installed.