Selection Assistant

The Selection Assistant gives you access to many powerful operations to help you mark your files for removal.

Open it with the Selection Assistant button on the left of the Duplicate files tab. Click the button again to close it.

The Selection Assistant works across the whole list, unless the list is filtered - then it only works on the files shown, and says Within filtered files. This lets you break a big job down into smaller parts.

Mark by group

Mark by group marks files by considering them group by group. Choose one of these:

• All but one file in each group - All except one file in each duplicate group is marked.
• Only one file in each group - Only one file in each duplicate group is marked. Other files are unmarked (unless Leave existing marks unchanged is ticked).
• All but one in the same group and folder - Like All but one file in each group, but also makes sure one file is left unmarked in each folder in the group.
• All but one matching set in each group - Sorts each group into matching “sets”, according to the preferences you set below, and then marks all but one set in each group. For example, with Smallest image dimensions ticked, only the largest images remain unmarked in each group; where all the dimensions are the same, nothing is marked. This mode doesn’t mark anything if no preferences are ticked.

Then click Mark by group.

Preferences

Under Preferring to mark, where possible (in order of preference): you choose which files you would prefer to be marked (removed). Smallest? Oldest? Missing tags?

For each group you can prefer to mark:

• Smallest image dimensions / Largest image dimensions (Image and Video modes)
• Shortest duration / Longest duration (Audio and Video modes)
• Oldest dates modified / Newest dates modified
• Oldest dates created / Newest dates created
• Smallest file sizes in each group / Largest file sizes in each group
• Longest file names in each group / Shortest file names in each group
• Longest folder path in each group / Shortest folder path names in each group
• Deepest folder depth in each group / Shallowest folder depth in each group
• A chosen column that Contains, Does not contain, Starts with or Ends with some text you type - for example, prefer to mark files whose Folder contains \Backup\.
• A chosen column’s Lowest/blank or Highest/non-blank value - for example, prefer to mark the file with the lowest Bit rate.

Only ticked preferences are used. Drag the ↕ handle to change their order - the first is the most important, and later ones are used to break ties. Click + to add another text or column preference. Reset returns the list to its defaults.

Important note: These are preferences only. If you are marking All but one file in each group, preferring files with “Copy” in the name, and there aren’t any files with “Copy” in that group, all but one file will still be marked. For stricter requirements, All but one matching set in each group may be the way to go.

Leave existing marks unchanged

The operation is carried out as normal, but nothing that is already marked is unmarked.

Mark by text pattern

This tool marks or unmarks files by matching some text in a particular column. It works on the entire list, or the filtered list if it is filtered.

• Column name - The column to look in, for example Folder or File Name.
• Equals / Contains / Starts with / Ends with / Does not contain - How the text must match.
• Text - The text to look for, or a regular expression.
• Is case sensitive - The match is case sensitive.
• Use Regular Expressions - Advanced users can use regular expression patterns, which let you match a pattern, similar to a wildcard - part of a word, or a range of numbers for instance. Duplicate Cleaner uses .NET regular expressions.
• Leave existing marks unchanged - Files that don’t match are left as they are. Otherwise, when you click Mark, files that don’t match are unmarked.

Click Mark to mark the matching files, or Unmark to unmark them.

Examples (with Use Regular Expressions):

[1-3]     Mark files containing the numbers 1, 2 or 3
^test     Mark files beginning with the word "test"

Note: This tool isn’t aware of duplicate groups, so be careful not to mark all copies of a file if you are intending to delete.

Mark by location

The Mark by location tool marks files by taking into account where their duplicates are. Choose a folder by typing its path or browsing for it, and tick Including subfolders to include the whole folder tree. Then either:

• Mark outside - Mark all files outside this folder that have a duplicate inside this folder. Tick Also preserve (unmark) files in this folder to unmark the files inside it.
• Mark - Mark the files in this folder that have duplicates elsewhere. Tick Also preserve (unmark) files elsewhere to unmark their duplicates outside it.

See Location marking for worked examples.

Other commands

• Unmark all - Unmarks all files in the list (or the filtered list).
• Invert marked files - Swaps the marked/not marked state of every file in the list (or the filtered list).

Undo

You can undo the last Selection Assistant operation by clicking Undo last marking operation. The number of marks the last operation changed is shown next to it.