How to Find and Delete Duplicate Files on Mac and External Hard Drives

2018-07-02 02:05:06 / Posted by Rosa Reyes to Utility Follow @ Rosa

In this guide, you will discover how to easily find duplicate files on both internal and external hard drives on Mac and get them deleted all at once.

As time goes, you may download and store more and more files on your Mac. The older your Mac is, the more likely your hard drive is running out of space.

To free up space on Mac, one solution is to get rid of unwanted files such as duplicate files. Another solution is to transfer part of your files to an external hard drive. And when you transfer files back and forth between your Mac and external hard drive, duplicate files may end up on both. With both solutions, it can help if you know how to find and remove duplicate files effectively.

Why find and delete duplicate files on Mac's internal and external hard drives?

Free up storage space

Duplicate photos, songs, videos and other types of files are useless but can take a considerably amount of storage space on Mac and external hard drive. By eliminating them using duplicate file finder software, you can effortlessly reclaim lots of disk space.

Stay organized and improve efficiency

Duplicate, triplicate or even more copies of the same file are useless and can cause confusion. Find and remove duplicate files and make it easier to manage and search files.

More efficient file transfer

Duplicate files can occur when you import files to Mac from an external hard drive where duplicates already exist. To prevent the creation of more duplicates and make transfer faster, one can locate and remove duplicate files on the external storage device first.


How to find and delete duplicate files on Mac and external hard drives using software

How to delete duplicate files on external hard drive mac such as photos that are stored on them? I have over 15000 duplicate photos on my Photos, half of it stored on the external HD. I tried to find these duplicates manually, but it was a waste of time and energy. Is there a duplicate file finder what could help me to find and remove these duplicate photos on Mac? Any help will be greatly appreciated. – A question from a Mac user

It’s possible to manually find and delete duplicate files on Mac and external hard drives. But what if there are thousands, tens of thousands or even more duplicates out there? You won’t want to find and delete them one by one by hand. The best way is to use duplicate finder software to scan your hard drives, find duplicate files scattered around, and remove them all at once.

Cisdem Duplicate Finder for Mac is designed to find and delete duplicate files on internal hard drive and external storage devices such as external hard drives, USB flash drives, SD cards, digital camera memory cards, etc.

  • This duplicate file finder uses MD5 value checksum algorithm and can do byte-by-byte checking. As a result, users can get accurate and safe results.
  • It can fast scan files and precisely identify duplicate photos, songs, videos, documents, archives and other types of files. True duplicates can be found regardless of file name and location.
  • You can also use Cisdem duplicate file finder to quickly find and remove duplicates in iTunes and Photos.
  • It provides 2 scanning methods, 3 preview modes, auto-select feature, 3 removal options, among other things, to make sure that users can get rid of duplicate files in an effective and safe manner.

Free Download

Download the free trial version of Cisdem Duplicate Finder now!

1. Step-by-step instructions on how to find and delete duplicate files on hard drives on Mac effortlessly

The steps below will show you how to find duplicate files on Mac and external hard drive using Cisdem Duplicate Finder.

Step 1Add hard drives or folders to scan

Connect your external hard drive to your Mac. Add files to scan by clicking the + button or by dragging and dropping. You can add one or multiple hard drives (internal or external, or both), or one or more folders to scan at the same time. It’s all up to you. Click the Scan button. You can stop scanning anytime, and real-time scanning results will be provided.

Note: Before the scan, it’s recommended to check out these tips to customize your duplicate files removal.

add mac internal hard drives and folders and external hard drives

Step 2View duplicate files

After the scanning finishes, click the Show Results button. You will find a pie chart overview of the duplicate files found on your internal and external hard drive on Mac. You can view all duplicate files under the All tab. They are also classified by file type including images, music, videos, documents, etc. Cisdem Duplicate Finder also allows you to sort the listed duplicate files by name, size, etc. and to search among them with keywords.

pie -chart overview of duplicate files on mac external hard drive

Step 3Preview duplicate files (optional but recommended)

Three preview modes are provided, along with built-in image viewer, media player, document reader, spreadsheets reader, etc. You can easily preview files without opening them. By previewing, you can know more about the duplicate files you are dealing with.

For example, before deleting duplicate photos on external hard drive on Mac, you can easily preview them in detail side by side.

find duplicate photos on external hard drive mac

Step 4Remove duplicate files

Cisdem Duplicate Finder for Mac uses Smart Select to automatically select duplicates by default. There also options such as Select Newest and Select Oldest. You can also select or deselect manually. Click the Delete button to get rid of duplicate images, audios, videos, etc. from your Mac and external hard drive.

Note: You can recover deleted files in Trash. However, please note that selected files on the external drive can only be erased permanently.

remove the duplicate files

2. Tips for customizing duplicate files removal

When you use Cisdem duplicate file finder to find and eliminate duplicate files on Mac and external hard drives, these tips can be useful.

Set minimum and maximum file size for scanning

Before you click the Scan button in the first step, click the gray setting icon in the upper right corner of the app’s interface. Under the General tab, you can easily specify the file size range to be scanned.

find and delete duplicate files cisdem duplicate finder setting

Select the removal option of your choice

Under General, you can choose Move to Trash, Remove Permanently or Move to Folder.

Ignore certain folders, files, or extensions

Under the Ignore List tab, you can exclude folders, files or file extensions from scanning. This would be especially useful when you scan the whole hard drive and want to skip certain folder(s).

find duplicate files on external hard drives mac exclude

Exclude or include hidden files when scanning

Also under the Ignore List tab, you can enable or disable the Ignore System Hidden Files and Folders option.


How to find duplicate files on Mac and external hard drives by hand

find duplicate files on external hard drive mac

How to find and delete duplicate files on Mac and external hard drive? There is more than one way. You can use software to identify and eliminate duplicates or do it by hand. It's not easy to manually find all the duplicate items on your internal and external hard drives on Mac. And it will take a lot of time and patience. Anyway, here’s how.

1. Go to Finder, choose a folder where you think duplicates may exist, say Documents, and use shortcut Command-F. A search bar will appear.

How to find duplicate files on external hard drive Mac by hand? Just choose your external hard drive in the Devices sidebar and then enter the said keyboard shortcut.

2. 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.

find and remove duplicate iles on external hard drive on mac by hand

3. Sort the listed files by name or other parameters, take a look at them, and find the duplicate files on Mac. You can move the unwanted ones to Trash.


In conclusion

Duplicate files can be a big space eater on your internal and external hard drives. If your computer does not have enough space, it may run slowly, and there may not even be enough free space for macOS update. By getting rid of useless duplicate files with the help of Cisdem duplicate file finder, you can make more storage room on your Mac.

Free Download

Download the free trial version of Cisdem Duplicate Finder now!

Do you think this guide on how to find and delete duplicate files on Mac and external hard drive helpful? Leave a comment and share your thoughts and opinions.

Most Popular Downloads

New

Duplicate File Finder Mac

Find and remove duplicate files on Mac.

19.99 29.99
Learn More
Hot

Contact Manager Mac

The Mac contact manager which keep contacts updated and clean

29.99 39.99
Learn More

Hot Articles

  • How to Recover Data from External Hard Drive on Mac

    There are also many users don’t know how to recover data from external hard drive. External hard drive data recovery sounds profound and difficult for those people who are not particularly proficient in Mac. Actually, it is not as hard as you imagine, an application, Cisdem Data Recovery can help you to recover deleted files from external hard drive easily.

  • How to Recover Data from Hard Drive on Mac?

    Many users don’t know how to recover data from hard drive on Mac. So when they deleted some data by mistake, they got worried. Actually, recover data from hard drive is not as difficult as you imagine. This article, I will list the detailed steps to recover files from hard drive, follow my instructions, recovering data from hard drive can be a piece of cake. Can’t believe? Continue to read it.

  • 5 Best Hard Drive Data Recovery Software for Mac

    Have you ever lost data from hard drive on Mac? How to recover the files lost due to accidental deletion, unexpected failure, formatting or other operation errors? Here we list 5 best hard drive data recovery for all Mac users to get data back from hard disk.

5 Comments Leave a Reply

  • Limnos

    I have a lot duplicate picture and movie files on my MacBook, this duplicate file finder app helped me free up 53GB space. I can't express my gratitude in words.

    2 years ago REPLY
  • Melissa

    I want to delete duplicate files from other storage device, not only from Mac or external hard drives, can Cisdem duplicate file finder help me do that?

    2 years ago REPLY
  • Rosa Reyes

    Hi, Melissa, Cisdem DuplicateFinder fully supports deleting duplicate files from Mac HDD, SSD, external hard drives, cameras, iPods, USB flash drives, memory cards, etc.

    2 years ago REPLY
  • Lareina

    My hard drive seems to create "duplicates" of all my files. I don't want to check it one by one. Cisdem DuplicateFinder did a great job with me.it works very well and remove duplicate files from my external hard drive quickly.

    2 years ago REPLY
  • Phoebe

    My mac was running out of space, and i transferred many files to external hard drive. I found many duplicate photos and music and tried to delete them manually. Oh, my god, I even didn't know there is such a nice tool like Cisdem DuplicateFinder that can help me remove them.

    2 years ago REPLY