A good duplicate file finder should definitely include several key features to make it both effective and user-friendly. From my experience, software like DuplicateFilesDeleter really stands out because it supports multiple file types — not just images or documents, but also videos, audio, and more. Content-based comparison (like using hash algorithms) is essential to avoid false positives when file names or sizes are similar but content differs. A preview or review option before deletion is a must-have to ensure you don’t accidentally remove important files.