Q: If two files look the same, why don’t they always match using hashing or byte-to-byte comparison?
A: Even if files appear identical, they may differ at the binary level due to metadata changes, encoding differences, or formatting variations. Traditional file-matching methods like hashing or byte-to-byte comparison detect these small differences, causing files that "look the same" to not match.
Q: What kinds of differences can prevent a match?
A: Several factors can cause this issue:
- Metadata Differences – Files store timestamps, author info, or unique IDs that make each copy slightly different.
- Encoding Variations – Text files, PDFs, and audio/video files may store data differently while still appearing identical to users.
- Format or Compression Differences – Images, videos, and audio files may have identical content but different levels of compression or file structures.
- Whitespace or Hidden Data – Text and document files may have different line endings (CRLF vs. LF), hidden characters, or small formatting variations.
Q: How does Duplicate Cleaner Pro solve this problem?
A: Unlike basic duplicate finders that rely on exact hashing or byte-to-byte comparisons, Duplicate Cleaner Pro provides smarter comparison modes tailored to different file types:
- Image Mode – Finds similar images even if they have been resized, rotated, or saved in a different format.
- Audio Mode – Matches audio files based on their actual sound content, even if they have different bitrates, metadata, or formats.
- Video Mode – Compares video content rather than just filenames or metadata, detecting duplicates even if they are slightly different encodes.
Q: When is hashing still useful in Duplicate Cleaner Pro?
A: Hashing works best for exact duplicate detection, such as finding true file clones with no modifications. However, when looking for similar content rather than strict duplicates, the specialized comparison modes in Duplicate Cleaner Pro are far more effective.