Anti-Twin vs dskDitto

Anti-Twin searches hard disks and other storage locations for duplicate or similar files. It can compare names, check file contents byte by byte, search for binary similarity, and compare images by their pixels. The image method can find similar pictures even when they have different compression rates or file formats. Search locations include local drives, USB flash disks, memory cards, shared network folders, and a second folder or path. Results can be selected automatically, exported as an Excel file, and sent to the Recycle Bin or deleted.

The program is free for private use and dates to 2003. The download page lists 32-bit and 64-bit Windows, and says it can run through Wine on Linux or Mac and on ReactOS. It can also be installed and started from a USB memory stick. Anti-Twin does not search the Internet or FTP servers, excludes files larger than 2 GB from comparisons, and has no restore function for deleted files. The site says it was maintained until 2012 and still runs on Windows 10 and 11.

dskDitto is a duplicate-file detector for Linux and macOS with a terminal interface by default and an optional experimental Raylib graphical interface. It scans local filesystem paths and directories using parallel processing, with optional virtual filesystem directories. Matching can use SHA-256, BLAKE3, exact filenames, or fuzzy content similarity; fuzzy mode starts at a 75% similarity threshold and disables automatic removal and link actions. Scan filters cover file size, directory depth, hidden files, symlinks, virtual filesystems, and filesystem boundaries. You can preview files, exclude folders, and use automatic selection. Results export to CSV, JSON, or plain text. With the explicit remove option, extra copies can be deleted or replaced by symlinks or reflinks. Reflinks require supported copy-on-write filesystems such as APFS, Btrfs, or XFS with reflink enabled. Source installation requires Go 1.22 or later; GUI builds also require Raylib and CGo. The project is free and released under the Apache license.