Duplicates

A photo library with multiple copies of the same file can quickly become overwhelming. Tonfotos simplifies your cataloging experience by automating the process of identifying and removing duplicates. It focuses on finding and deleting exact duplicates—that is, files with identical binary image contents—while preserving any versions you've edited or tagged. If you're looking to locate visually similar images instead, check out our blog post with an overview of tools that specialize in that task.

Tonfotos not only helps you clean up your current library by removing duplicates but also offers features to prevent re-importing duplicate files when adding new photos. This ensures your library stays organized and efficient over time.

What is considered a duplicate in Tonfotos

Tonfotos is dedicated to automating duplicate search and removal. That's why it detects as duplicates only the exact copies of the same file.

Let's consider some of the situations you may meet with:

What are these image files	Will Tonfotos detect them as duplicates?	Explanation
Exact copies that are located in different folders.		The contents of these files are exactly the same, so Tonfotos will detect them as duplicates.
One of the exact copies was renamed without editing any of the contents.		Changing the filename doesn't change the contents, so Tonfotos will detect them as duplicates.
A RAW photo and the copy that was made from it to prepare for publication.		Preparing the photo for publication includes converting the photo to a different format. Its contents will change.
The same photo in different formats, for example, TIFF and PNG.		The contents of the same image in different formats differ, and choosing one to delete automatically is not possible.
An original photo and a corrected and edited version.		Applying filters, cropping the photo, or any other edits make the edited photo different, and only you can decide which edits you want to keep.
The photos are from a series of shots taken in the same spot.		At first glance, you might think they are the same photo, but there will be subtle differences. It's up to you to choose the best.
One of the photos had its metadata edited or tags added.		This is a non-obvious case where the photos will look the same, but will still be considered different. If Tonfotos automatically removed a duplicate to which you added tags or corrected the location and date, your work on organizing would have been lost.

Removing duplicates from the entire library

The Remove duplicates... feature lets you remove duplicates across the whole library, decide for each set of duplicates which copy should be kept, and automate this process as far as possible. This feature works best if you have a principal library location, which stores photos you want to keep. In the Delete Duplicates dialog, you will then be able to remove the duplicates of those photos from all other auxiliary locations or temporary folders.

To remove duplicates across locations:

1. Select File > Remove duplicates...
2. In the Delete Duplicates dialog that opens, you will see all the duplicates that Tonfotos found.
   • For duplicates that are found in the different library locations, the Located in column shows the name of the location where the duplicated files are 1. Click Delete All 2 against this location to delete all duplicates in that location. The Identical to column 3 shows the name of the location where the files will remain. To manually review the photos that would be deleted, click To Album.
   • If some photos are duplicated within the same subfolder 4, Tonfotos can simply keep only one of the copies for each set of duplicates and delete the other copies in the same folder. Click Delete All.
   • If some photos are duplicated within the same location but in different folders, Tonfotos can't tell which copies to remove. To review the photos manually, click To Album 5 and see the next section.

The Duplicates album

In the Delete Duplicates dialog, click To Album 5 against a location to automatically generate the Duplicates album for this location.

The Duplicates album will be populated differently depending on where the duplicates are found.

• For duplicates that are found in different library locations (both Delete All and To Album buttons are shown in the previous dialog), only the files that should be deleted are shown in the Duplicates album. If you delete all these files, the originals in the other library location will still be kept.
• For duplicates within the same location, all the duplicated files are shown in the Duplicates album. Tonfotos doesn't know which of these files you consider originals. Review this album and delete the extra copies, but be careful not to delete the last copy too.

Review the Duplicates album and remove the copies you don't need. When only one photo remains, it is no longer shown in this album. If you remove all duplicates, the album will be empty.

Removing copies of the selected files

Once your library is indexed, the File information pane shows you all duplicates of a selected photo, which lets you go to the other copies and select which copy to keep and which to delete. This is the best method for fine control over duplicate removal, and you can apply it to multiple files at the same time.

1. Press CtrlP or click in the upper right to show the File information pane.
2. Under the filename and dates of creation and modification, you can see the full path to the photo 6. If it has duplicates, you can also see clickable paths to all the duplicates 7: click on a path to go to the location of that copy.

3. When you decide which copy to keep, right-click it and select Delete all duplicates of selected file(s) to remove all other copies. Do the same for several files to remove all extra copies of all selected files.

Preventing duplicate import

After tidying up your photo library, all that remains is to make sure that the new photos you add don't contain any more duplicates.

To avoid duplicates during import from your devices, check the Duplicates: Ignore checkbox.

Additionally, check the Ignore older than: checkbox and specify the date of your last import. This is particularly useful if you have edited photo metadata, as such changes make the files appear different. By setting a date filter, you can prevent re-importing these photos, keeping your library clean and free of unnecessary duplicates.

Move to main archive

You may already be using the Move to main Archive feature to move your photos from a temporary folder into the principal library location and organize them into Year/Date formatted subfolders at the same time. This feature also prevents adding duplicates to your principal library: Tonfotos detects duplicates during the move and prompts you to delete the extra copies.