Best Open-Source Duplicate File Finders 2026: 6 Options Compared

Duplicate finders look simple until you delete the wrong copy, so the best ones are built around safety. Most work by grouping files of equal size, then comparing hashes, so the only decision left to you is which copy to keep. The open-source tools here split into graphical and command-line camps. Czkawka and dupeGuru have windows you can click through. dupeGuru can also match similar pictures and music, not only exact copies, which is useful for photo libraries but needs more review. The command-line tools, fdupes, jdupes, rmlint and fclones, are faster and scriptable, and they suit servers and large archives where you want to preview a list, then act on it. fclones and jdupes are aimed at speed on big collections, while rmlint can produce a script you read before running it. The trade-off is risk against automation. Automatic deletion is fast, but a bad rule can remove the only good copy, and hard links or symlinks can fool a naive tool. Start with a report, not a delete, and run your first pass on a copy of the folder. Keep one rule that you always preserve: the file in your main library, not the one in Downloads. On photos, remember that two files with identical pixels but different metadata count as different to a hash-based tool.

Czkawka

Open source GUI and CLI that finds duplicates, empty folders and large files. The core is MIT, and it is a good graphical starting point.

Price: Free (free, open source) (Czkawka pricing, checked 2026-10-22).

Platforms and license: Windows, Linux, macOS, FreeBSD, Android. MIT (core) (open source) (license source).

Project activity: 34.6k GitHub stars · latest release 12.0.2 (Sep 9, 2026) · last commit Sep 16, 2026

Best for: Graphical duplicate cleanup.

Worth knowing: Finds duplicates, empty folders, big and temporary files; GTK GUI superseded by Krokiet.

dupeGuru

GPL-3.0 graphical tool that also matches similar pictures and music, not just exact copies. Review matches carefully before deleting.

Price: Free (Free and open source) (dupeGuru pricing, checked 2026-10-23).

Platforms and license: Linux, macOS, Windows. GPL-3.0 (open source) (license source).

Project activity: 7.9k GitHub stars · latest release 4.3.1 (Jul 9, 2022) · last commit Sep 7, 2026

Best for: Photo and music libraries.

jdupes

MIT command-line duplicate finder and remover focused on speed. Easy to script in shell jobs, but it has no graphical interface, so review reports before deleting.

Price: Free (Free and open source) (jdupes pricing, checked 2026-10-23).

Platforms and license: Linux, Windows, macOS, BSD. MIT (open source) (license source).

Best for: Fast scans on large folders.

rmlint

GPL-3.0 command-line tool that finds duplicates and other lint, and can output a script you review before running it.

Price: Free (Free and open source) (rmlint pricing, checked 2026-10-23).

Platforms and license: Linux, FreeBSD, macOS, Solaris. GPL-3.0 (open source) (license source).

Project activity: 2.4k GitHub stars · latest release v2.10.3 (Mar 22, 2025) · last commit Oct 16, 2026

Best for: Reviewing a deletion script first.

fdupes

MIT command-line duplicate finder, simple and long established. It has fewer features and less speed than newer tools such as fclones, but it is widely packaged.

Price: Free (Free open source) (fdupes pricing, checked 2026-10-24).

Platforms and license: Linux, macOS. MIT (open source) (license source).

Project activity: 3k GitHub stars · latest release v2.4.0 (Mar 30, 2025) · last commit Apr 14, 2026

Best for: Basic scripted duplicate checks.

fclones

MIT command-line duplicate finder and remover written for large collections. It has no graphical interface, so you review its reports and act on them yourself.

Price: Free (Free open source) (fclones pricing, checked 2026-10-24).

Platforms and license: Linux, macOS, Windows. MIT (open source) (license source).

Project activity: 3k GitHub stars · latest release v0.35.0 (Mar 3, 2025) · No commits since Mar 3, 2025

Best for: Very large file collections.

Worth knowing: Command-line duplicate finder and remover.

Which one to pick

• You want to click through results: Czkawka
• You have a large photo library with near-duplicates: dupeGuru
• You want to review a script before anything is deleted: rmlint
• You scan terabytes on a server: fclones