Using Finder to Find and Delete Duplicate Mac Files. If you would rather avoid installing a third-party app, use Finder to find and delete duplicate Mac files instead. This method is incredibly time-consuming and can lead to more mistakes, but it doesn’t risk your security. DupeGuru (Free) dupeGuru is an open source duplicate file finder Mac, Windows, and Linux users can download, install, and use completely free of charge. Thanks to its quick fuzzy matching algorithm, dupeGuru is highly efficient and capable of discovering hundreds of duplicates in a very short amount of time.

This article will show you how to find and delete duplicate files on external hard drive on Mac easily and quickly.

External hard drives are often used for backup purposes such as Time Machine backups. They can also be used to transfer files from computer to computer. Duplicate files may slowly accumulate over time as you use your external hard drive. To make effective use of the storage space on your drive, it’s a good idea to find the duplicate files on it and get them deleted. The article talks about two ways for Mac users to remove duplicate files from external hard drive.

The Best External Hard Drive Duplicate File Finder

• Support macOS 10.10 or later
• Find and delete duplicate photos, audios, videos, docs, packages and more
• Work with Mac’s internal drive, external HD, flash drive, etc.
• Also find similar images
• Remove duplicates from iTunes, Music, Photos & iPhoto
• Make it easy, quick & customizable to scan for duplicates
• Allow you to conveniently preview files within the app
• Let you delete duplicate files with 1 click
• Offer useful features like Ignore List and Auto-Select

Find and delete duplicate files on external hard drive on Mac in 1 minute or less

How to find duplicate files on external hard drive on Mac? The best way is to use duplicate file finder software like Cisdem Duplicate Finder for Mac. It is compatible with macOS 10.10 or later, including macOS 10.15 Catalina.

Delete duplicate files on external hard drive on Mac in 4 steps

Step 1. Add your hard drive(s) to scan

Download and install Cisdem Duplicate Finder. Open it.

Click the add icon and add hard drives or folders to scan. Click the Scan button.

• To find duplicate files on an external hard drive, add the drive alone. Also, you can add specific folders from the drive.
• To find duplicate files between two drives (internal or external), add these drives.
• Likewise, you can use the app to easily scan for duplicate files across multiple drives or folders, external or internal.

Step 2. View and preview duplicate files

Once it finishes scanning, you will be presented with the results window. All the duplicate files are listed under the All tab. You can also view them by file type, such as Images, Music and Documents.

There are three preview modes (Thumbnail, List and Info), allowing you to preview pictures, media files and documents without leaving the app. The preview feature can be especially useful when it comes to deleting duplicate photos on external hard drive. You can also zoom in or out for better view.

Step 3. Select duplicates for removal

This duplicate file finder will automatically select duplicate copies for you to delete. Additionally, it provides four selection rules .

• Smart Select
• Select by Priority
• Select Newest
• Select Oldest

You can choose one of them based on your preference. Also, it allows you to select or deselect manually.

On a side note, when it comes to handling similar images, there are eight selection rules available.

Step 4. Delete duplicate file on external hard drive with 1 click

Make sure that you have selected the unwanted duplicates. Click the Delete button in the bottom right corner. A message will appear. Click Yes to confirm the deletion.

The duplicates will be permanently removed from your external HD. If it were an internal disk instead of an external one, there would be more removal options available such as Move to Trash.

Note: You can stop the scan process at any time, and real-time scan result will be provided. Don’t eject your external hard drive while the scan or removal is going on.

Cisdem Duplicate Finder main features:

• Detect and delete duplicates on Mac, external SSD/HDD, USB flash drives, SD card, Google Drive and more
• Find duplicate photos, videos, audios, Word documents, spreadsheets, PDFs, ebooks, packages, archives, etc.
• Also find similar images
• Remove dupes from Photos, iPhoto, iTunes & Music
• Scan for one or multiple folders or drives simultaneously
• Allow you to scan for duplicates by file content or filename
• Automatically select files for you to eliminate with 1 click
• Also provide multiple selection rules
• Easy to use
• Free up space on Mac, external hard drive, etc.
• Help you better organize your files

Tip: How to reduce time to scan external hard drive for duplicate files

How Do I Delete Duplicate Files On My Mac For Free

This Cisdem external hard drive duplicate file finder uses MD5 value checksum algorithm and does byte-by-byte comparison when scanning. It generally only takes seconds to scan thousands of files. For a significantly large amount of files, it will take more time.

Here’s the good news! You can exclude files and folders from the scan so as to lessen the time it will take.

• Exclude folders Before you hit the Scan button, click the settings icon in the top right corner. Go to the Ignore List tab. Click the add icon to add specific folders or sub-folders for exclusion.
• Exclude file types Go to the Ignore files of particular extensions section. Click the add icon to enter file extensions. If you enter MP3, it will skip all the MP3 audio files when scanning your external HD for duplicates.
• Exclude files by size Switch to the General tab. There, you can set the minimum and maximum file size. For example, if you aim to get rid of large duplicate files and quickly free up space on your external hard disk, then you can set the scan to skip all small- and medium-sized files.

In addition to what has been mentioned in the tip above, there are also other options in settings . By customize settings options when needed, you will be rewarded with a more efficient duplicate removal.

Manually find and delete duplicate files on your external hard drive in Finder

How do Mac users find and delete duplicate files on external hard drive? The best way is to use a duplicate file finder for Mac. You can also do it by hand. It's not as hard as it seems. However, it can be a waste of time and energy if there are a lot of duplicate files on your external hard drive. Anyway, here’s how.

Step 1. Plug your external hard drive into Mac. Go to Finder. In the Devices sidebar, select the external drive.

Step 2. Use shortcut Command-F. A search bar will appear.

Step 3. Select Kind among the available search parameters. Select the file kind of your choice in the second dropdown list. Also choose a specific file format if needed.

Step 4. Sort the listed files by name or other parameters, preview and compare, and find the duplicate files. You can move the unwanted ones to Trash.

Use Terminal

You can also identify duplicate files on external hard drive or Mac’s internal hard drive with Terminal. Note that it only identify duplicates. You still need to delete the files manually. Terminal comes with every Mac.

Step 1. Go to Finder > Applications > Utility. Find and open Terminal.

Step 2. If you want to find the duplicate files in a folder, say Downloads, you can use the cd command by typing cd ~/Downloads and press the return key.

How To Remove Duplicate Files On Mac Free

Step 3. Enter the command: find . -size 20 ! -type d -exec cksum {} ; | sort | tee /tmp/f.tmp | cut -f 1,2 -d ' ' | uniq -d | grep -hif – /tmp/f.tmp > duplicates.txt. Press return.

Step 4. Open the file duplicates.txt and you will find a list of duplicate files. Now you can manually find and delete them.

Why there are so many duplicate files and how to avoid them

Why are there so many duplicate files on my Mac? It’s not uncommon to have duplicate files on your Mac and external hard drives. As a matter of fact, duplicate files are almost inevitable.

They can be there due to multiple imports of the same file, multiple copies of backup, app (such as iTunes) bugs, etc. They can occur when you unknowingly transfer files to your external hard disk where the same files already exist. Another cause is file compression. Sometimes we compress photos to make them smaller in size for emailing or uploading. In a case like this, there can be duplicate copies of the same photos. They are identical in content but different in size.

Whatever the cause is, it’s important to clean them up. By doing so, you can free up storage space and keep your files more organized. It will also help if you know how to prevent them from occurring.

• Delete photos and videos from SD card after you transfer them to your Mac
• Set your Mac to detect duplicate files while importing
• Be aware that resizing or editing photos will lead to almost duplicate files
• Avoid unnecessary backups
• Use duplicate file finder software on a regular basis

In conclusion

Above are the two common ways on how to find duplicate files on external hard drive on Mac. Duplicate files can waste space your internal and external hard drives. By getting rid of useless duplicate files with the help of software like Cisdem Duplicate Finder, you can free up storage space on your external hard disk. Do you think this guide on how to identify and remove duplicate files helpful? Leave a comment and share your thoughts and opinions.

Is the hard disk on your Mac majorly occupied with duplicate files? If yes, Duplicate Files Fixer is the tool for you to remove all such redundant files.

• This duplicate finder tool can help to delete duplicate photos, docs, music, videos, spreadsheets and even emails! It is fast and easy to use by simply dragging and dropping folders you wish to scan onto Easy Duplicate Finder. This app will then delete the unnecessary files from your Mac.
• Alongside file recovery, boot imaging, and storage visualization, Disk Drill is an excellent tool for finding and deleting duplicate files for Mac. To use Duplicate Finder, simply download Disk Drill, within the installation dialog drag it to the Applications Folder, and then launch the app. You are now on your way to saving your storage space.
• Unnecessary duplicate files on your Mac are space wasters. To find and remove duplicate files, you should consider MacPaw's Gemini 2 software. To take your file management to the next level, check out MacPaw's CleanMyMac X. What is Gemini 2? MacPaw's Gemini 2 uses algorithms to detect duplicate files, no matter the location on your Mac.
• Reclaim wasted disk space on your HDD, SSD or in the Cloud and speed up your computer by removing duplicate files today. Easy Duplicate Finder™ is a powerful app that uses smart technology to identify all kinds of duplicate files. It's super simple drag-and-drop interface and intuitive scan modes make removing identical files a breeze!

Duplicate files and similar files are different, you know. But, both can be a curse for your storage space at a time. Gemini 2 has a smarter way to recognize and remove similar files from your Mac. We tried this feature and the results were great. When we scanned a folder or directory for duplicate files, Gemini 2 also found similar files.

You can recover a lot of disk space by removing multiple file copies from your Mac. Duplicate Files Fixer removes these files effortlessly. It's an easy way to retrieve storage space instantly!

Accurate identification of duplicates

Duplicate Files Fixer identifies all duplicate file formats accurately. You can find identical texts, photos, audio, and video files with this extremely user-friendly software.

Backup can be easily created

You need not worry about retrieving files, in case you want to. Duplicate Files Fixer gives you the option to backup all your files before you delete them.

Folders exclusion supported

You might not want to scan all your folders for duplicates. The software gives you the option to exclude the files you do not want to scan. Now that makes your work easy.

Supports external device scanning

All the files and folders you want to scan might not be stored in your Mac. /photo-border-app-mac/. So you can simply attach pen drives and external disks and Duplicate Files Fixer will scan them too.

Provides rapid & accurate results

So you have got loads of files to be scanned. But that’s perfectly alright. Duplicate Files Fixer will give you a speedy yet accurate scan irrespective of volume of files you have.

Criteria for scanning can be set

You can set the scanning criteria for the software to get a more comprehensive scan result. You can also have a look at your scan history and adjust the settings for better results.

How it Works

• Step 1: Install the software on your Mac first
• Step 2: Add the files and folders you want to scan
• Step 3: Click on the Scan button to begin the process
• Step 4: Preview the list of duplicate files on your Mac
• Step 5: Auto-mark or select the identical files manually
• Step 6: Confirm that you want to delete selected files
• Step 7: Voila! You are done. It really is a hassle-free tool

What Our Users Say

Our Users are extremely happy with the app

Delete Duplicate Files Mac App Download

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Don’t worry about the identical files on your system! Keep sharing and downloading files as many files as you want. All you have to do is to install Duplicate Files Fixer on your system. It’s going to get rid of all identical files in no time at all.