qarmin/czkawka

Czkawka (pronounced "tch-kav-ka", Polish for "hiccup") is a free, open-source desktop app for cleaning up unnecessary clutter on your computer. It goes well beyond just finding duplicate files, it can also detect nearly-identical images (even if they have different resolutions or watermarks), similar-sounding music tracks, empty folders, temporary junk files, broken files that can no longer be opened, files whose extensions don't match their actual content, and much more. The problem it solves is simple: over time, computers accumulate a lot of redundant and wasted storage. You might have the same photo saved in three places, a music collection full of near-duplicates, or thousands of empty folders left behind by old software. Manually finding and removing this stuff is tedious. Czkawka automates it. It works by scanning the folders you point it at, then running smart comparisons, hashing files to find exact duplicates, using image-fingerprinting algorithms to find visually similar pictures, and comparing audio metadata or content to match similar songs. Results are displayed so you can review and decide what to delete, rather than blindly auto-removing anything. You would use this whenever your hard drive is getting full and you suspect it's partly due to redundant files, or before migrating a large photo or music library and wanting to clean it up first. The project is written in Rust, which gives it speed and reliability. It runs on Linux, Windows, macOS, and even Android, and offers both a graphical interface and a command-line mode for automation.