Freedom251 › Disk Cleanup Software
ncdu
What ncdu is
ncdu is free, MIT-licensed, text-mode software for locating files and directories that consume disk space. Its interactive curses browser is designed to work on remote servers without a graphical setup. It can scan external drives and export directory trees as JSON or compressed binary files; the binary format supports browsing trees too large to fit in memory. From the browser, users can delete files or directories, refresh data, and open a shell, with deletion and shell access optionally disabled. A read-only option disables deletion, and using it twice also disables shell spawning. Version 2.5 added parallel scanning, disabled by default and enabled with a thread-count option. The site lists a Zig-based stable release and a maintained C-based LTS release, with the C branch behind in features and performance. The Zig version requires Zig 0.14 or 0.15, and its maker cautions that the language and compiler are somewhat unstable. A web export browser accepts supported export files, but uploaded data is visible to anyone with its URL and expires after 30 days.
Who it suits
ncdu suits users managing disk space on Linux, macOS, Windows, or remote systems without a graphical interface. It is also useful when exporting directory trees for later browsing.
What it does well
- Interactive text-mode directory browser
- Works on remote servers
- Scans external drives
- Exports JSON and compressed binary trees
- Read-only mode can disable actions
What to know first
- No treemap view
- No application-size or file-type breakdown
- Zig build requires Zig 0.14 or 0.15
- Web uploads are visible by URL
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| ncdu | MIT-licensed software · Linux static binaries and packages for listed systems | Free |
As dev.yorhel.nl lists them, read 8 Oct 2026. The maker's own page has the final word.
Verdict
ncdu offers focused disk-usage analysis with interactive actions and export formats suited to large trees. Choose the release branch carefully and protect exported files because shared links are publicly viewable.
Facts from ncdu's own pages
- Application sizes
- No · dev.yorhel.nl, 23 Sept 2026
- Build requirements
- The listed Zig version requires Zig 0.14 or 0.15, and the maker cautions that the Zig language and compiler are somewhat unstable. · dev.yorhel.nl, 8 Oct 2026
- Compatibility limits
- The maintainer says users combining the software with proprietary software or operating systems such as macOS or Windows are mostly on their own for support. · dev.yorhel.nl, 8 Oct 2026
- Export formats
- It can export directory trees as JSON or in a compressed binary format that supports browsing trees too large to fit in memory. · dev.yorhel.nl, 8 Oct 2026
- Exportable reports
- Yes · dev.yorhel.nl, 23 Sept 2026
- External drive scans
- Yes · dev.yorhel.nl, 23 Sept 2026
- File actions
- The browser can delete files and directories, refresh directory data, and spawn a shell; delete and shell actions can be disabled. · dev.yorhel.nl, 8 Oct 2026
- File-type breakdown
- No · dev.yorhel.nl, 23 Sept 2026
- Free plan
- Yes · dev.yorhel.nl, 23 Sept 2026
- Interface
- It provides an interactive curses-based view of which directories use disk space. · dev.yorhel.nl, 8 Oct 2026
- License
- The software is distributed under the MIT license. · dev.yorhel.nl, 8 Oct 2026
- Platforms
- The maker lists Linux static binaries and packages for Linux, BSD, AIX, Solaris, macOS, and other systems, plus a Windows binary from another site. · dev.yorhel.nl, 8 Oct 2026
- Purpose
- ncdu is a text-mode disk usage analyzer designed to find space hogs, including on remote servers without a graphical setup. · dev.yorhel.nl, 8 Oct 2026
- Read-only mode
- The manual documents a read-only option that disables deletion, and with a second occurrence also disables shell spawning. · dev.yorhel.nl, 8 Oct 2026
- Scanning
- Version 2.5 added parallel scanning, which is disabled by default and can be enabled with a thread count option. · dev.yorhel.nl, 8 Oct 2026
- Scan scope
- files_folders · dev.yorhel.nl, 23 Sept 2026
- Support
- The maintainer welcomes bug reports by issue tracker or email but makes no promise to act on feedback or fix every bug. · dev.yorhel.nl, 8 Oct 2026
- Treemap view
- No · dev.yorhel.nl, 23 Sept 2026
- Version choices
- The site lists a Zig-based stable version and a maintained C-based LTS version; it says the C branch lags in features and performance. · dev.yorhel.nl, 8 Oct 2026
- Web export browser
- The linked export browser accepts ncdu JSON, compressed JSON, and binary export files; uploads are visible to anyone with the URL and expire after 30 days. · ncdu.blicky.net, 8 Oct 2026
Where ncdu stands on Freedom251
- Disk Cleanup Software#3 of 22
- Disk Space Analyzers#19 of 105