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Duff Resurrected is the revival of DUFF (DUplicate File Finder), Jeremy B. Smith’s 2002-2005 open source tool (sourceforge.net/projects/dff). The Visual C++ 6 sources were ported to Visual Studio 2022/2026, Unicode and 64-bit, with dozens of crashes and bugs fixed and the search made many times faster by grouping files before comparing them byte by byte.
Find duplicates by content, name, text or MP3 audio data, narrow them down with filters, mark the copies you don’t need automatically (oldest, biggest, in a certain folder, ...) and delete, move or export them. New: an Advanced page with rule expressions, saved profiles, a two-pane Compare Directories window, dark mode, long path support, skip lists for junctions and mount points, a built-in user guide and a working command line tool.
Program is opened via the duff.exe
Features
- Finds duplicate files by binary content, file name, text content or MP3 audio data
- Fast: files are grouped by size and hashes first, only real candidates are compared byte by byte
- Filters on size, date, attributes and file contents to narrow the search down
- Advanced page: combine layers and filters into rule expressions with AND, OR, NOT and groups
- Automatic marking of the copies you do not need: oldest, newest, biggest, smallest, by name or by location
- AND/OR between markers, several location directories, one copy kept per directory
- Delete to the recycle bin or permanently, move (optionally keeping the directory structure), send to a program or save the list
- Two-pane Compare Directories window with marks on both sides and its own processing
- Skip list for junctions, mount points and hard-linked directories; junctions and symlinks are never followed
- Long path support (over 260 characters) and files over 4 GB
- Saved profiles and automatic restore of the last session
- Dark mode, resizable pages, DPI aware, modern folder picker with drag and drop
- Sizes in bytes, KB, MB, GB or TB; CSV export; UTF-8 log
- Built-in user guide (F1)
- Command line tool duffc.exe for scripted searches, marking, deleting and CSV output
- No registry, no internet access: all settings are plain text files under %APPDATA%
- Unicode, 64-bit and 32-bit builds for Windows 7 and later; Visual Studio 2022/2026 with CMake
- Free and open source
Project Samples
