How NotchStar finds duplicate files
To find duplicate files, open the Disk tab, pick Duplicates and press Scan for duplicates. NotchStar compares the contents of your files, not their names, and lists each set of identical copies. The oldest copy of each set is the one it keeps.
Where and what it looks at
- Folders: Downloads, Documents, Desktop, Pictures, Movies and Music inside your home folder.
- Files of 1 MB or more. Smaller files are skipped.
- Hidden files and the insides of app and other packages are skipped.
- Symbolic links are skipped, and so are hard links. A hard link is the same file under two names, and removing one frees nothing.
How it decides two files match
- Group files by size. Different sizes cannot be identical.
- For groups with the same size, hash the first and last 64 KB of each file. This is cheap and drops most false candidates.
- For files that still match, compute a full SHA 256 of the whole content. Only files with the same full hash are called duplicates.
Sets are sorted by how much space you could get back, and the sum is shown on the button.
Removing copies
Tick sets, then press the button that reads Move (size) of copies to Trash. The oldest file in each set stays, the rest go to the Trash. Check the keeper’s location first. The oldest copy might sit in a folder you would rather not keep it in.
Limits
It does not look outside those six folders and it is not a general backup check. A large scan can take a while, see why a Disk scan is slow. The Disk feature page lists the other sections, and the Trash step explains how to undo a move.
