Anti-Twin vs Dup Detector

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.

Dup Detector is a free, open-source desktop application for finding duplicate files and reclaiming storage space. It runs on Linux, macOS, and Windows. Smart hashing compares file sizes first, then partial content, and performs full content hashing when needed. The maker says smart hashing can scan 10,000 or more files per second. Multithreaded scanning is supported, and the app describes its memory footprint as minimal. Dup Detector identifies duplicates but does not remove them automatically, so users decide which files to keep or delete. The maker says the code is fully open source and welcomes inspection and contributions. It states that the app has no analytics, telemetry, or data collection. The Free plan costs nothing, is available forever, and includes cross-platform use. GitHub issues and Discord provide support and feedback channels.