Czkawka vs dupeGuru
Czkawka and dupeGuru are two free, open-source duplicate finders. Both run on Linux, macOS and Windows, both find exact duplicates and similar pictures, and both cost nothing. They differ in speed, in what happens when you press delete, and in whether anyone is still releasing them.
We make DuoBolt, a paid duplicate finder, and measured both tools in the same session as our own. The numbers below are ours, on our hardware, with the method published. DuoBolt’s own times are in the table for reference.
The Short Answer
Section titled “The Short Answer”- Czkawka is the faster of the two on every tier we measured, hashes with BLAKE3, is still developed, and does far more than duplicates — empty folders, broken files, bad extensions and more. Its delete is permanent unless you change a setting.
- dupeGuru sends files to the Trash by default and has a dedicated music mode. Its last release was in July 2022.
Benchmark Results
Section titled “Benchmark Results”Apple M2 Max, macOS 27.0, 20 September 2026. Each tool’s own cache cleared before every run, 1 KB minimum file size, exact duplicates only. Czkawka 12.0.2 is the czkawka_gui GTK build that brew install czkawka installs; dupeGuru is 4.3.1. Lower is better.
| Storage | Czkawka | dupeGuru | Czkawka’s lead | DuoBolt, for reference |
|---|---|---|---|---|
| Internal SSD — 394 GiB, 1.69M files | 1m3s | 7m17s | 6.9× | 38s |
| USB-C SSD — 797 GB | 5m39s | 9m42s | 1.72× | 5m17s |
| NAS over SMB — 1.09 TiB | 11s | 17s | Too close | 10s |
Where the gap comes from: the internal SSD tier is a source tree of 1.69 million mostly small files, so it measures what each tool spends per file, and that is where the two are furthest apart. On the external SSD the bus limits both, and the gap narrows to 1.72×. On the NAS almost nothing shares a size, so the scan is mostly a walk over the share; dupeGuru ran once there, on a tier where repeat runs drifted by up to 30%, so 11 against 17 is a lean rather than a result.
One check that does not depend on trusting the table: when ~115 GiB of Photos libraries was taken out of the external SSD scan, Czkawka shed 221 seconds and dupeGuru 238 — both close to the ~227 seconds that reading those bytes costs at the drive’s measured 542 MB/s. Both were genuinely reading the data. The benchmarks page has the full table.
Feature Comparison
Section titled “Feature Comparison”| Feature | Czkawka | dupeGuru |
|---|---|---|
| Platforms | Linux, Windows, macOS, FreeBSD | Linux, Windows, macOS |
| Price | Free, open source | Free, open source |
| Hashing | BLAKE3 by default, or CRC32 / XXH3 | xxHash, with MD5 as a fallback |
| Default delete | Permanent, unless Move deleted files to trash is enabled | Send to Trash, with direct delete as an option |
| Similar pictures | Yes | Yes — Picture mode |
| Music | Same Music, by tags or by content | Music mode, by tags or by content |
| Similar videos | Yes | No |
| Other cleanup tools | Empty folders and files, big files, temporary files, broken files, bad extensions, invalid symlinks, and more | No |
| Front ends | Krokiet (recommended), the GTK app (final version 12.0), and a command line | One desktop app |
| Latest release | Active | 4.3.1, July 2022 |
Czkawka’s list of tools is from its README. dupeGuru’s switch from MD5 to xxHash is in its 4.3.0 release notes; its help pages still describe MD5.
Deleting Safely With Either One
Section titled “Deleting Safely With Either One”Czkawka removes files outright unless Move deleted files to trash is turned on in its settings, and it documents no review step before a removal and no way to restore after one. Turn the setting on before the first cleanup.
dupeGuru sends to the Trash by default, which is recoverable until the Trash is emptied. Its own FAQ lists network storage as a case where sending to the Trash can fail, and offers “directly delete files” as the workaround — which turns a recoverable removal into a permanent one. On a NAS, that is the moment to slow down.
Where DuoBolt Fits
Section titled “Where DuoBolt Fits”If you are on Linux, or want a free tool, the choice is between these two, and on speed and maintenance Czkawka is the stronger one.
DuoBolt is a third option on macOS and Windows: it is paid, with a free tier that scans and cleans, and it was the fastest of the three on the first two tiers above and tied on the NAS. Where it differs most is around the delete: a mandatory Review Selection screen before anything is removed, and a history that can rebuild a file from a byte-identical copy after a permanent delete.