Czkawka vs dupeGuru

Czkawka is a free tool for locating duplicate and unnecessary files, empty folders, similar images, and related items. Its tools can find duplicate and empty files, temporary and large files, similar videos, and duplicate music. Scans can target user-selected directories and files, with matches determined by file name, size, full-file hash, or a combination of size and name. Features include file preview, automatic selection, folder exclusions, and moving items to the Recycle Bin or Trash. The project provides graphical and command-line frontends, an Android frontend, a reusable core library, and Python bindings. It says the software uses multithreading and caching to help scans and later rescans, and that it has no internet access and collects no user information or statistics. Czkawka is listed for Android, Linux, macOS, and Windows. GTK 12.0 is the final release for that frontend, and no more GTK binaries are planned. Krokiet prebuilt binaries have no mandatory runtime dependencies, although its similar-videos tool requires ffmpeg at runtime.

dupeGuru has no write-up on Specifiction yet; its figures are above.