Ext4 quietly holds back 5% of every partition for root, and on a 2 TB data drive that is 100 GB you paid for and can never write to. The reserved block count made sense when disks were 40 GB, less so now. The best apps for reclaiming Linux disk space either show you where the free space actually went, tune filesystem defaults so you get it back, or clear cruft the package manager left behind. We picked eight that solve one of those problems well and stay out of the way the rest of the time.
What to look for in a Linux disk tool
Not every disk tool does the same job. Before installing anything, decide which problem you actually have.
- Visual map of what is using space, so you can see runaway logs or a forgotten
~/Downloadsat a glance - Terminal-only option for headless servers where a GUI is not available
- Filesystem tuning that changes the ext4 reserved block percentage safely, without reformatting
- Package cache and journal cleanup that survives apt, dnf, pacman, and flatpak side-by-side
- Partition-level control for shrinking, growing, or moving a partition on the same disk
- No sudden deletions. Anything that touches system directories should show a preview first
Quick comparison table
| App | Best for | Interface | Free plan | Standout feature |
|---|---|---|---|---|
| Baobab | Visual scan of home directory | GTK GUI | Free (open source) | Ring-chart map ships with GNOME |
| ncdu | Headless servers over SSH | Terminal | Free (open source) | Sorts on export, deletes with d |
| Filelight | KDE users who like radial charts | Qt GUI | Free (open source) | Click any wedge to zoom in |
| QDirStat | Power users hunting duplicates | Qt GUI | Free (open source) | Cushion treemap and cleanup actions |
| BleachBit | Cache, logs, and browser cruft | GTK GUI | Free (open source) | Previews every delete before running |
| Stacer | Ubuntu users who want one dashboard | Electron GUI | Free (open source) | Startup, services, and cleanup in one panel |
| GParted | Resizing and moving partitions | GTK GUI | Free (open source) | Live-USB workflow for offline changes |
| Disks (GNOME) | Tuning ext4 reserved blocks | GTK GUI | Ships with distro | Wraps tune2fs -m in a UI dialog |
The apps
1. Baobab, best for a quick visual scan
Baobab ships as GNOME Disk Usage Analyzer on Ubuntu, Fedora, Debian, and most GNOME-first distros. Point it at /, ~, or any mount and it walks the tree into a ring chart. The outer rings are subfolders, the inner ring is the parent, and hovering reveals the byte count. It handles a full home partition in seconds because it caches the scan.
Where it falls short: No delete action inside the app itself. It shows you the offender, then opens the folder in Files so you can act. That is a feature for cautious users and an annoyance for fast ones.
Pricing:
- Free: fully functional, no paid tier
- Paid: none
Platforms: Linux (GNOME, but installs on KDE, Xfce, and others)
Download: gnome.org/baobab or sudo apt install baobab / sudo dnf install baobab
Bottom line: Install this first if you have never scanned your home directory. It is the shortest path from “my disk is full” to “oh, there is the 40 GB Steam prefix I forgot about”.
2. ncdu, best for headless servers
ncdu runs in the terminal, which makes it the right pick when you are SSH’d into a VPS with no display server. Point it at a mount, wait a few seconds, and it presents a scrollable list sorted by size. Press d on any row to delete after a confirmation, or g to switch to a graphical bar. Export scans to JSON with -o and you can compare disk usage between two moments in time.
Where it falls short: Deletion is instant with only one confirm dialog. Fine for a log file, less fine when you scroll too far and hit d on a home directory.
Pricing:
- Free: fully functional
- Paid: none
Platforms: Linux, BSD, macOS (via Homebrew)
Download: sudo apt install ncdu / sudo dnf install ncdu / dev.yorhel.nl/ncdu
Bottom line: The tool you reach for when there is no desktop environment. Keep it in your dotfiles.
3. Filelight, best for KDE users
Filelight is the KDE take on the same visual-scan idea. Instead of a ring chart, it draws a radial map where each wedge is a folder. Click a wedge to zoom in, right-click to open it in Dolphin. Its rendering is quicker than Baobab on large trees because it uses cached inode data instead of re-stat’ing every file.
Where it falls short: The Qt build feels out of place on GNOME, and it pulls in KDE Frameworks as a dependency chain when installed outside KDE.
Pricing:
- Free
- Paid: none
Platforms: Linux (KDE-native, installs on any DE)
Download: apps.kde.org/filelight or sudo apt install filelight
Bottom line: If you already run KDE Plasma, install Filelight and skip Baobab. Otherwise the extra Qt libraries are hard to justify.
4. QDirStat, best for power users
QDirStat is the direct descendant of KDirStat, the treemap tool a lot of Linux users grew up with. It renders a cushion treemap where every rectangle is a file, sized by bytes. Colour-coded by extension, so a screen full of red usually means video files. It ships a “Cleanup Actions” menu that you can extend with your own shell snippets, which turns it into a lightweight file manager for oversized directories.
Where it falls short: The cushion treemap takes a moment to learn if you have never used one. The custom cleanup actions are powerful and can also delete a lot in one click, so read the shell command before you save it.
Pricing:
- Free
- Paid: none
Platforms: Linux, Windows (via port), macOS (via Homebrew)
Download: github.com/shundhammer/qdirstat
Bottom line: Pick QDirStat when the ring charts have shown you where space went and you want a scriptable cleanup layer.
5. BleachBit, best for cache and log cleanup
BleachBit cleans what the disk analyzers leave behind: browser caches, apt / dnf / pacman leftovers, journal logs older than a set threshold, thumbnail caches, and ~/.cache/* folders that grow without bound. Every category has a “preview” mode that shows byte counts before deletion, so you can uncheck the ones you would rather keep.
Where it falls short: BleachBit’s Firefox cache cleanup can invalidate logged-in sessions. Uncheck the “cookies” and “session” boxes if you do not want to log in again after a run.
Pricing:
- Free
- Paid: none
Platforms: Linux, Windows
Download: bleachbit.org or sudo apt install bleachbit
Bottom line: Run once a month with cookies and sessions unchecked. Reclaims a surprising amount from /var/log and ~/.cache on a system that has been up for six months.
6. Stacer, best for one-panel management
Stacer wraps disk cleanup, startup application management, service control, and package uninstall into a single Electron dashboard. On Ubuntu and Ubuntu-based distros it is close to a full system utility. On other distros it works but shows fewer services because it depends on systemd unit paths.
Where it falls short: The Electron shell has a memory footprint that is out of proportion to what the app does. On a laptop with 4 GB of RAM it feels heavy.
Pricing:
- Free
- Paid: none
Platforms: Linux (systemd distros)
Download: github.com/oguzhaninan/Stacer or Snap Store
Bottom line: Newer Linux users often reach for Stacer as their first cleanup tool. It works well enough for that, but pair it with Baobab so you know what is being deleted.
7. GParted, best for partition-level work
GParted does not clean files, it moves and resizes the container they live in. If your /home is on its own partition and running out, GParted grows it by shrinking the neighbour. Boot from the GParted Live USB when a partition is currently in use, since ext4 shrinks and moves are safest offline.
Where it falls short: Partition operations carry real risk. A crash mid-shrink can leave the filesystem unrecoverable. Back up before running any resize that is not a growth.
Pricing:
- Free
- Paid: none
Platforms: Linux (live-USB works on any x86 machine)
Download: gparted.org or sudo apt install gparted
Bottom line: Not for cleanup, but for the case where the disk itself is partitioned wrong. Every Linux user should have a GParted Live USB in a drawer.
8. Disks (GNOME), best for tuning ext4 reserved blocks
Disks is the GNOME Disk Utility that ships with most distros. Its usual job is mounting and formatting drives. Its hidden trick is the “Edit Filesystem” dialog, which lets you change the reserved block percentage on ext2, ext3, and ext4 without dropping to tune2fs manually. Set the value to 1% on a data disk and you get most of that 100 GB back. Leave 5% on / where the OS still needs headroom.
Where it falls short: The reserved-block dialog is buried three menus deep and does not warn that lowering the value on / can leave the OS unable to write logs when the disk is nearly full. Use it on data partitions, not the system one.
Pricing:
- Free (ships with GNOME)
- Paid: none
Platforms: Linux (GNOME desktops; KDE Partition Manager offers a similar dialog)
Download: apps.gnome.org/DiskUtility or sudo apt install gnome-disk-utility
Bottom line: The only tool on this list that goes after the reserved-blocks problem directly. Pair it with Baobab and you have covered both “what is using space” and “why do I have less than I paid for”.
How to pick the right one
Pick Baobab if you have never scanned your home directory and want a visual answer in under a minute.
Pick ncdu when the machine has no GUI. Keep it in your server dotfiles.
Pick Filelight if you already run KDE and prefer radial charts over rings.
Pick QDirStat if the analyzers have done their job and now you want scriptable cleanup actions.
Pick BleachBit when the apt cache, browser cache, and log rotation have gotten away from you.
Pick Stacer as a friendly first tool if you are new to Linux and want everything under one panel.
Pick GParted when the problem is the partition layout, not the files inside it.
Pick Disks (GNOME) when you realize ext4’s default 5% reserve is eating a data partition. Set it to 1% and reboot.
FAQ
What is the best way to see what is using space on a Linux drive? Baobab if you have a desktop, ncdu if you are on SSH. Both walk the tree in seconds and sort by byte count.
How do I get back the 5% that ext4 reserves for root?
Open GNOME Disks, select the partition, click the gear icon, choose Edit Filesystem, and set Reserved Block Percentage to 1 for data disks. Leave 5% on the system disk. Or run sudo tune2fs -m 1 /dev/sdaN from a terminal.
Is BleachBit safe to run on a daily driver? Yes, with cookies and browser sessions unchecked. The category-level previews show exactly what will be deleted before you commit.
Can I resize a mounted ext4 partition?
Growing a mounted partition is safe with resize2fs. Shrinking is not, and GParted’s own guidance is to boot from the Live USB before shrinking /.
What is the difference between BleachBit and Stacer? BleachBit focuses on cache and log cleanup with per-category previews. Stacer bundles cleanup with startup, services, and package management in one Electron panel. Use BleachBit for regular cleanup, Stacer for occasional system-wide tidying.
