How to set Auto Select rules in Duplicate File Finder

Duplicate File Finder’s Auto Select option is a feature that allows you to automatically select multiple duplicate files for removal.

You can configure Auto Select rules so that when you use it, the program automatically marks unnecessary duplicates for deletion, depending on factors such as their names, location, modification date, and more.

Select duplicate files

There are 13 Auto Select rules that can be used all together or one at a time to help you choose unnecessary duplicates for removal. Let’s see how the Auto Select rules work and how you can configure them for yourself.

The Always select in specified folder rule

  • Apply the Always select in selected folder rule if you know that in a particular folder(s) there are lots of duplicates that you can delete without a doubt.

    According to this rule, when you click Auto Select, the app will suggest removing duplicates from the specified folders.

    By default, the Downloads folder is included in the list. You can click on the plus button to add any other folder or click on the minus button to exclude them.

  • how to select duplicate files in folders

For example, let’s say there are two duplicate files in the group. One file is located in the Downloads folder, and the second is in the Pictures folder. Following the Always select in the Downloads folder rule, Auto Select marks the duplicate file in the Downloads folder for removal and not in Pictures.

how to select duplicate in downloads folder

The Never select in selected folder rule

  • Apply the Never select in selected folder rule when you need to keep files in a particular folder(s) and remove their copies from other folders.

    According to this rule, when you click Auto Select, the app shows all duplicates, but it suggests files from other folders for removal (never the specified folders).

    The iTunes and Music folders have been pre-selected in advance, which keeps their files from being marked for deletion. You can click on the plus button to add any other folder or click on the minus button to exclude one.

  • never select in folders rule

For example, this time let’s say you have two duplicate files. These files have the same name, type, size, content, and date of creation. But one file is located in the Documents folder, and another one is in the Music folder.

According to the Never select in the Music folder rule, Auto Select keeps the file in the Music folder and marks the duplicate file in the Documents folder for removal.

never select duplicate in folders

You can exclude all the folders from the Always select and Never select rules. However, if any folder is specified in these rules, the app will always apply these two rules first of all.

The Select with suffixes contained in the file name rule

  • The Select with suffixes contained in the name rule serves to determine all possible duplicates based on the suffixes they ordinarily are given.

    When you create a duplicate file in Finder, a suffix is added to its name. Usually the suffix is a number or additional word, like filename copy.png or filename 2.png with space in between.

    According to this rule, Auto Select marks all duplicate files with the specified suffixes for deletion. By default, there are 31 variants of the word “copy” in various languages on the list.

  • auto select rules with suffixes

If you have a habit of renaming copies of files using another word, you can add it to the rule. Just click on the plus button and type the word. In this case, the application will choose to remove duplicate files based on your suffix as well.

For example, there are three duplicate files in the group. These files have the same type, size, content, and date of creation. However, they have different names:

  • parrots.jpg
  • parrots copy.jpg
  • parrots 2.jpg

According to the Suffixes rule, Auto Select marks for removing the duplicate files that contain specified suffixes in their titles.

suffixes rule

The Select with prefixes contained in the file name rule

  • The Select with prefixes contained in the name rule serves to determine all possible duplicates based on the prefixes they ordinarily use. As with suffixes, new copies of files can acquire prefixes in their names.

    When you create a duplicate file, a prefix can be added to its file name, usually a number or additional word, like copy of filename.png with space in between.

    According to this rule, when you click Auto Select, all unnecessary duplicate files with the specified prefixes are selected for deletion. By default, variants of the word “copy” in different languages are added to the list.

  • prefixes rule

Again, if you usually rename copies of files according to a pattern, you can add the prefix to the list. For this, click on the plus button and type the word or phrase. Adding more search terms helps the app to find duplicate files based on the additional criteria.

For this example, let’s say there are three duplicate files in the group. These files all have the same type, size, content, and date of creation, but different names:

  • bluebird.jpg
  • copy bluebird.jpg
  • copy of bluebird.jpg

Following the Prefixes rule, Auto Select marks duplicate files that contain specific prefixes in their titles for removal.

identical files

Now let’s look at another example. You have three identical files. Their names are

  • Birds
  • Birds photocopy
  • Birds photo copy

According to the Auto Select rules, all files with the word “copy” and a space in their names are duplicate files, whereas files with “copy” in the name but without a space are not considered duplicates. That is why the Auto Select option marks only one duplicate file for removal, “Birds photo copy”, while another duplicate file, “Birds photocopy”, it kept as an original.

autoselect rules for fuplicate finder

Because of this, we recommend caution when adding suffixes/prefixes to the rules lists to avoid misunderstandings.

If a duplicate is in the Never Select folder, it will not be selected by any rule. If the duplicate is in the Always Select folder, it will be selected first regardless of suffixes and other rules.

The Select in Photos Library rule

  • Enable the Select in Photos Library rule to keep your Mac’s Photos Library free of duplicates.

    In this case, the app will compare files in your folders with the files in the Photos Library. If duplicates are found, unnecessary files inside or outside the Photos Library.

    For example, if your iCloud storage is full, you may decide to download your photos and videos to your Mac and get rid of their copies in Photos. However, the content from the Photos Library would be duplicated on your Mac.

  • duplicates in photo library

If you want to free up space in Photos using the Select in Photos Library rule, choose Select duplicates inside Photos Library. In this case, you will keep the files on your Mac, and Auto Select will mark the duplicates in Photos Library for removal.

If you want to keep some files in Photos and remove the same files from your Mac, choose the Select duplicates outside Photos Library option of this rule.

The Select by full path rule

  • Enable the Select by full path rule if you want to mark duplicate files based on their folder location. You can choose the filepath in alphabetical order or in reverse alphabetical order.

    In this example, you have three duplicate files that have the same size, type, name, and content. They are stored in the following directories:

    HD/Users/userName/Dropbox/Unsorted/playtime.jpg
    HD/Users/userName/Google Drive/2018/playtime.jpg
    HD/Users/userName/OneDrive/Documents/Boom/playtime.jpg

  • Select duplicate by full path rule

Auto Select analyzes the whole path, and where the differences begin. If you choose to select files by the full path in alphabetical order, Auto Select will mark files for removal in the Dropbox and Google Drive folders.

select by full path rule

The Select by name rule

  • Enable the Select by name rule if you have duplicate files with different names.
    You can choose to select duplicate files for removal in alphabetical order or reverse, depending on their names.

    For example, you have duplicate files with the following names:

    • blue and red birds.png
    • red and blue birds.png

    If you set to select files by name in alphabetical order, Auto Select will mark for removal the “blue and red birds.png” duplicate file because its title starts with “b”.

  • Select duplicate files by name rule

The Select by parent folder rule

  • Enable the Select by parent folder rule when you want to mark files for removal based on the names of the parent folders in which duplicates are stored. Here you can also choose to consider folder names in alphabetical order or vice versa.

    For example, you have duplicate files in two folders, and their paths are:

    • Music/Summer/First/playlist.mp3
    • Music/Summer/Second/playlist.mp3

    The parent folders are named First and Second. If the Select by parent folder in alphabetic order rule is enabled, the Auto Select will mark for deletion the duplicate file in the First folder, as its name starts with “f”.

  • Select by parent folder

The Select by full path length rule

  • Use the Select by full path length rule when you want to choose duplicates for removal based on their path length. You can choose to mark files with a shorter or longer path.

    For example, you have two duplicate files with different paths:

    • HD/Users/Bob/Pictures/LA 2019/IMG_101
    • HD/Users/Bob/Unsorted Photos Summer 2019/IMG_101

    The paths of files have a length of 37 and 48 characters. So if you enable the Select by full path length rule by longer path, the Auto Select will mark for removal the second duplicate file for removal as its path is longer.

  • Select by full path length rule

The Select by name length rule

  • Enable the Select by name length rule if you have duplicate files with different names.

    You can choose to select duplicate files for removal, depending on the shorter or longer name.

    For example, you have two duplicate files with different names:

    • two birds.png
    • blue and red birds.png

    If you set the rule to Select by the shorter name, the Auto Select will mark for removal the “two birds.png” duplicate file for removal because its name is shorter.

  • Select by name length rule

The Select by parent folder name length rule

  • The Select by parent folder name length rule helps to pick duplicate files based on the name length of the parent folder in which they are stored. You can set to select files by the shorter or longer name of the parent folder.

    In this example, you have two duplicate files, and they are located in different parent folders:

    • HD/Users/Bob/Pictures/2019/IMG_101
    • HD/Users/Bob/Pictures/Summer 2019/IMG_101

    The parent folders are 2019 and Summer 2019. So if you enable the Select by parent folder name length rule by a shorter path, the Auto Select will mark the first duplicate file for removal.

  • Select by folder name length rule

The Select by modification date rule

  • Use the Select by modification date rule when you want to select duplicate files by the date of their modification. The duplicates are chosen depending on the oldest or most recent time of modification.

    For example, let’s say you downloaded a picture and, after a few weeks, downloaded it again. Now you have two duplicate files with different modification dates.

    When you enable the rule to select files for removal based on the oldest modification date, Auto Select will mark the file that you downloaded first.

  • Select by modification date rule

The Select by nesting level rule

  • Enable the Select by nesting level rule when you want to remove duplicate files that are located deeper or higher in the directory tree.

    For example, let’s imagine that you have a Pictures folder with tons of images that you decide to sort. You create a new folder labeled Year 2019 inside it and copy desired images there. Then, you add a new folder Summer 2019 inside the Year 2019 folder and copy the relevant pictures there.

    In this situation, you would have duplicate files among three folders from the same directory. To choose unneeded duplicate files, you can enable the Select by nesting level rule to pick the files located higher to be removed.

  • Select by nesting level rule

In this situation, you would have duplicate files among three folders from the same directory. To choose unneeded duplicate files, you can enable the Select by nesting level rule to pick the files located higher to be removed. So, when you click Auto Select, the app will mark duplicate files from the Pictures and Year 2019 folders, so that you can preserve only the sorted files in the Summer 2019 folder.

nesting level rule

How does Auto Select work

Now that you understand how each of the individual rules function, we want to share with you the general algorithm of Auto Select rules:

  • The application will first take into account the Always Select, Never Select, and Suffixes/Prefixes rules. If these rules do not apply, then the next enabled rules are enabled.
  • The application uses Auto Select rules according to their position in the list, from top to bottom. You can change the order of the rules by dragging them up or down in the Auto Select rules window.
  • If there are no differences between the files for the chosen rules, none of the files will be selected by the Auto Select command. For example, if all duplicate files in a group are in the Always Select folder, none of them will be selected for deletion. If all duplicate files in a group have the suffix “copy”, then none of them will be marked for deletion. If the rule is set to select the newest files and the dates are the same, no file will be selected for removal.
  • You can change the Auto Select rules whenever you want, but be sure to deselect all previously selected files before using a new rule.
    Use the Command+D shortcut to deselect files, change the Auto Select rules, and then you can use the Auto Select command.
  • The Auto Select option will never select all duplicates in the same group. At least one file from a group always remains unselected. This is necessary to save your data.

You can disable and change these rules from scan to scan, depending on the specific data that you want to preserve.

How to reset the Auto Select rules?

  • If you want to reset all the Auto Select rules you have added to the basic settings, follow these steps:

    1. Open Preferences.
    2. Select the Advanced tab.
    3. Press the Reset Application Settings button.
  • reset auto select rules

We hope we’ve made it clear how to configure the Duplicate File Finder’s Auto Select rules correctly so that the finding and removing unnecessary duplicates is even more convenient.


Read more about removing duplicates on your Mac

How to delete duplicate photos on Mac
How to find and remove duplicate files in OneDrive
How to find and remove duplicate files on macOS
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