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DupExFind and remove duplicate files on Linux — safely, and fast.
DupEx (Duplicate Exterminator) is a high-performance tool for Linux that finds byte-identical files and makes it easy to choose which ones to remove — fast, and without putting data at risk. It does one thing, and does it perfectly.
Built for the one use case where getting it wrong is not an option.
At a glance
- Full control — nothing is deleted or moved to the trash without confirmation
- Rules do the tedious part — duplicates can be picked by age, path, name or regular expression, for deletion or for protection, whole folders included
- Optional byte-for-byte verification — confirms every duplicate by direct comparison, not by hash alone
- Adapts to the storage — SSDs, hard disks and network shares are detected up front, and the scan strategy is tuned to each
- Repeat scans are much faster thanks to a hash cache
- Filters that narrow the scan down — size range, file types, include/exclude patterns, same name or same extension only
- Built for large collections — search, sort and clean up hundreds of thousands of files
- File-manager integration — one or more folders/files can be scanned straight from the context menu
- Usable entirely with the keyboard — shortcuts for frequent actions
- Available as deb, rpm, tar.gz (install script), AppImage, Flatpak and Snap
- No ads, no spyware, no tracking
- One-time purchase, no subscription
- Available in 23 languages
- Native Linux app
Highlights
Safety by architecture
DupEx never deletes without confirmation. Reference folders are automatically protected, auto-select never selects every file in a group, and before deleting the affected files are listed in full — with a warning if a group would lose its last copy.
Optional byte-for-byte verification
By default a full-file BLAKE3 hash identifies duplicates. Turn on byte-for-byte verification and every match is confirmed bit by bit — so a hash collision can never cause a wrong deletion, not even in theory.
Fast funnel algorithm
Files are filtered in stages — group by size, sample hash, pairwise sampling, full hash — so the expensive reads only ever touch a handful of candidates. AVX2/SSE4.1 SIMD across all CPU cores via OpenMP. It started as an AVX2 byte-comparison in assembly; everything else grew around it.
Group & reference system
Compare a backup against the original without reporting the duplicates inside the backup itself. Hardly any other duplicate tool does this.
Automatic tuning
A lightweight pre-scan detects the storage medium (SSD / HDD / NAS), file-size distribution and available RAM, and tunes all scan parameters automatically — no manual tuning needed.
Real-time results
Duplicate groups appear while the scan is still running, sorted by path, name, type or size. They can be reviewed, selected and even partly deleted before the scan finishes.
Rule-based selection
Select oldest, keep the shortest path, filter by regex — DupEx selects thousands of duplicates in seconds by those rules, ready to be moved to the trash or deleted permanently.
Right from the file manager
Right-click one or more folders/files in Nemo, Nautilus, Dolphin, Caja or Thunar and scan them with DupEx — across Cinnamon, GNOME, KDE, MATE, XFCE, LXDE, LXQt and COSMIC.
Built for power users
Log levels, I/O tuning, memory-mapping control, a database hash cache (alongside the system cache), extended thread statistics and full keyboard operation. Handles files well beyond 2 GB — with no unsafe code, no compiler warnings, Valgrind-checked.
Screenshots
DupEx ships with both a light and a dark theme — toggle to preview either. Click any screenshot to enlarge.
Free demo
Scan, find and inspect all duplicates, and see how much space could be freed — full speed, no limits. Deleting files is reserved for the paid editions.
Editions & pricing
Launch offer — 20% off every edition through October 31, 2026, with code DUPEX20.
All prices in EUR and include any applicable tax. The exact tax for the buyer's country is calculated and shown at checkout by Lemon Squeezy, our Merchant of Record and the seller of record. Business customers can enter a VAT ID at checkout.
Full version: one-time purchase, no subscription, no ads, no spyware — internet is only needed to unlock the full version.
Included in every paid edition
- Full-speed scanning across all CPU cores
- Move duplicates to the trash or delete them permanently
- Reference & protected folders plus keep-rules
- Automatic tuning for SSD, HDD and NAS
- Light and dark theme
- One-time purchase — no subscription
Frequently asked questions
Which Linux systems does DupEx run on?
As a package on all current 64-bit Linux desktops from Debian 13 (Trixie), Linux Mint 22 (Wilma), Ubuntu 24.04 LTS (Noble Numbat), Fedora 40, openSUSE Leap 16 and Zorin 18 onwards, and on rolling releases such as Arch Linux, CachyOS and openSUSE Tumbleweed. As a Flatpak or Snap DupEx also runs on older releases (for example Ubuntu 20.04 or Linux Mint 20).
Can DupEx delete the wrong file by accident?
DupEx never deletes without confirmation: reference folders are protected, auto-select never selects every file in a group, and deleting is preceded by a warning if a group would lose its last copy. Byte-for-byte verification can be switched on as well, confirming every match bit by bit.
Is this a one-time purchase or a subscription?
A one-time purchase. There is no subscription and no recurring fee.
What is the difference between the editions?
Only the number of devices: Single license = 1, Standard = 3, Pro = 5. The feature set is identical across all paid editions, and you may use your licence at work. Business is for companies buying centrally — invoiced to the company, VAT ID, more than five devices.
Does the free demo have any limits?
No limits on scanning: the demo finds and inspects all duplicates at full speed. Only deleting files is reserved for the paid editions.
Does DupEx need an internet connection? Is my data private?
DupEx runs locally and works offline; an internet connection is only needed to unlock the full version. No ads, no spyware — files and their contents never leave the computer.
Can I get a refund?
Yes — see our Refund Policy in the footer for the conditions.
Where can I download DupEx?
Under "Free demo" above. The release page carries deb, rpm, tar.gz, AppImage and Flatpak; the Snap comes from the Snap Store.
Where do I report a bug or request a feature?
In the issue tracker of the dupEx release repository on GitHub, which the download button above leads to. A short description, the distribution and the dupEx version are enough — the version is shown in the About dialog.
Technical stack
System requirements
DupEx runs on 64-bit Linux distributions from about 2024 onwards (GTK 4.12 and glibc 2.39 or newer), as a Flatpak or Snap on older ones too.
- Operating system: 64-bit Linux (x86-64)
- GTK 4.12 and glibc 2.39 or newer (package libgtk-4-1) — for deb, rpm, AppImage and tar.gz
- Flatpak and Snap do not have this limitation: they bring both of their own and therefore also run on older releases
- Scanning from the file manager requires one of: Nemo, Nautilus*, Dolphin, Caja*, Thunar, COSMIC Files, PCManFM, PCManFM-Qt, Krusader or Konqueror
- (*) Nautilus needs the nautilus-python bindings, Caja the caja-actions extension — the setup points this out and can install them
- Processor: SSE4.1 (present in virtually all CPUs since ~2010); AVX2 acceleration is used automatically when available
- Memory: scales to available RAM, with a dedicated Low-RAM profile for small machines
- Storage: local SSDs and HDDs, external drives and network shares (NAS) are supported
- Internet: required only to unlock the full version