Unless you’re ultra-scrupulous in the way you use your PC, there’s every chance that it contains duplicate data. It’s all too easy to copy a file twice from a USB flash drive or digital camera, or open one and inadvertently save it under a different name without making any changes.
Multiple copies of multiple files not only wastes disk space (though that’s hardly an issue these days), but it also makes file management difficult. After all, how can you be sure which photo of your aunt Freda is the best one to print when you have seven copies of it?
The solution is to perform a duplicate file search on your PC and delete the unwanted copies, The catch is that you can’t just do this by file name — you need to examine the contents, too. Doing that manually takes far too long, but thankfully you can automate the process. Here’s how.
Finding duplicate documents
DupeGuru is a free download for Windows, Mac and Linux. We’re using the Windows version here, but the steps are much the same for Mac and Linux.
Step 1: Download and install DupeGuru
Download and install DupeGuru from www.hardcoded.net/dupeguru. Be sure to use the correct version for your operating system, including 32-bit or 64-bit versions of Windows. There’s nothing unusual to watch out for during the installation.
Step 2: Select a folder to scan
Launch DupeGuru and you’ll be asked to select which folders to scan. It’s worth limiting this scan so that it completes quickly while you familiarise yourself with the program, so click the + button and select your My Documents folder, then click the Scan button.
Step 3: Check the list of found files
DupeGuru will then scan the selected folder and display a list of files that it thinks are identical, based on their content, with the ‘original’ file highlighted in blue. The list also shows the size of each file for a quick manual comparison and a Match column that shows how confident DupeGuru is that the files are the same.
Step 4: Delete or move the duplicate files
Once you’re satisfied that the duplicate files have been correctly identified, select Mark All from the Mark menu to select the duplicates. Then, using the Actions menu, you can delete the duplicates or move them all to another folder, regardless of where they are currently. This is often a better option, since you can delete the files later, when you’re completely sure you don’t need them.
Step 5: Find duplicate files in other ways
Select Preferences from the View menu to see DupeGuru's various options. Here you can select whether to compare files by Filename, Contents or Folders (duplicate folders). If you use the Filenames option, you can also select the Filter Hardness to match similar filenames, as well as identical ones — the ‘harder’ this setting, the more exact the match.
Finding duplicate images
Finding duplicate images is rather more involved, since a computer can’t compare the content of an image file in the same way as a document. So this requires a separate application — DupeGuru Picture Edition. This is also a free download for Windows, Mac and Linux and works in almost the same way.
Step 1: Download and install DupeGuru
Download and install DupeGuru as before. It used to have a separate version called DupeGuru PE (Picture Edition), but now all the features are rolled into the standard edition. Again, be sure to use the correct version for your operating system, including 32-bit or 64-bit versions of Windows.
Step 2: Scan for duplicate photos
Launch the program and select one or more folders to scan. This might take longer than scanning for documents, as images are generally bigger file sizes. When it’s complete, be sure to use the Details view to compare the duplicate images to check they’ve been correctly identified before moving or deleting them. Though DupeGuru is remarkably accurate.
Step 3: Find photos that are almost idenitcal
DupeGuru can also identify images that are not quite duplicates, such as two photos of the same subject where you moved the camera slightly. You may not want to keep these near-duplicates, so select Preferences from the View menu and reduce the Filter Hardness slider to match more images.
You’ll need to experiment with this to get the best results and be sure to only delete the files you no longer want — DupeGuru has no idea which ‘original’ you want to keep.