If your Mac starts to run slow, the first thing to check is if your space is running low. It is generally recommended that 10% of your total space should be free on your Mac to get the most out of it. If you run out of your last few gigabytes, now is the time to do some housework and get some space back on your own.
Over time, a Mac can accumulate a large collection of duplicate files that take up this valuable space so this is a good place to start. However, finding and deleting them can be time consuming if you do it one by one, so in this article we show you quick ways to clean your system from these criminal doppelgangers.
Why do I have duplicate files?
In most cases these will be mis-downloaded (due to double-clicking on a link), mail and message attachments, a complex filing system, a bad habit of dragging things to your desktop, or many other possibilities. Unless you’re an unusually good Mac user, the duplicates are going to turn out one way or the other.
How to find duplicates using Finder
Finding duplicate files on your system is possible using the Smart Folder feature in Finder.

- Start by opening the Finder app.
- Navigate to File> New Smart Folder in the menu.
- Click the ‘+’ button in the upper right corner.
Now you can search for documents, photos, music, or other file types How do you pick results. When ordering according to their name any duplicate should be brought which can be easily identified. (If it does not appear in the order of the name, click on the drop down menu to go to the list view).

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Just be sure to check the date to see if it’s a true duplicate – for example you don’t want to delete the wrong version of an important document. (If you do not see the date, right-click and select Add Date, you can even add the last opening date to choose the right one to delete.

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While this is possible, it is far from ideal. There may be a problem that you have given different names to the same file and this method will not show it.
This is a time consuming process and the time spent plowing through a long list of files can be better spent by visiting the App Store and purchasing software that will instead find duplicates for you and delete them safely.
The best app for finding duplicate files on Mac
The Mac App Store has a number of duplicate file finders that will automatically search your system and recommend file doubles that can be removed.
Lots of freebies including Duplicate File Finder Remover and Duplicate Cleaner. You can also try the Find Duplicate feature of Parallels Toolbox, which offers a valid free trial for seven days and we prefer Gemini 2 from MacPa which has a valid three day trial.
Most apps offer similar features, so you ask the app to scan your hard drive, then a list of duplicates is presented, along with the original file so you know which ones are safe to delete.
All of the apps listed above will definitely free up some space on your Mac and you can always start with the free one then move on to a paid version later if you find the features useful.

You’ll need to switch to a paid version, usually for advanced features like deleting duplicate folders, hidden files, and similar functions.
Gemini 2
One of our favorite duplicate removal applications, and one with a good level of positive feedback from customers is Gemini 2: The Duplicate Finder, which is free to download and includes a free three-day trial. It offers a Smart Cleanup feature for অ্যাপ 19.99 / £ 18.49 as an in-app purchase. While the name may be more in line with a dystopian sci-fi novel, the app is a powerful tool for your Mac.
Once you allow scanning your folder, Gemini 2 will go ahead and scan for duplicates. It took us about seven minutes to scan our 256GB drive (with about 150GB of files). Upon completion of the scan, a duplicate of 12.63GB was found.
Gemini 2 automatically selected 45.6MB files – these were duplicate images. We’ve been able to delete them automatically by clicking on Smart Cleanup.

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However, there were still GBs of files left that were ready to be removed. It is possible to sort through duplicates by choosing which version to keep. To see all the duplicates that Gemini has found, click on Select More ৷ You can flick through these and choose what you want to lose. It’s a bit of a drag that you have to do it manually, but it’s still easier and more visible than using Finder. If you don’t really need it, you can choose to delete each instance of the file or image.

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Since we were removing photos, Gemini reminded us that recently deleted photos from our photos also need to be removed, alternatively we can wait up to 30 days for them to be automatically deleted. You can review what has been trashed and ‘put back’ any file if you have a second thought (but you need to take this step before you can delete the contents of the recently deleted folder.)
Gemini can not only find duplicates of any file on your hard drive, but it also searches external drives and cloud storage services such as Google Drive and Dropbox. All of this is accompanied by the ability to instantly replace deleted files.
Read more about Gemini – and other related apps from the firm, such as CleanMyMac X – on MacPaw’s website.
Duplicate File Finder
Duplicate File Finder can scan your home folder, or you can select a specific folder or drag the file. There are two versions of the software – a free version and a Pro version The latter adds a few additional features, such as the ability to merge folders and restore duplicates. The Pro version for a Mac costs 19.99 / £ 20.99
You need to allow it to scan various folders and sections on your Mac. The software will then scan for duplicates with some fancy graphs representing the type of files it has found.

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You can then click the Cleanup Tips section to find some files to delete. Each step has a detailed overlay showing what you need to do. Just click on x to remove it.
In each case, you can review the duplicate before deleting it. Like Gemini you can remove duplicates or you can delete all versions of files or images. The review and removal option gives you a visual view of where the duplicate file was located, which may be effective.

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You can also choose Auto Select to pick duplicates for you – you can even refine the selection. You can review them before removing them

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Duplicate File Finder creates a duplicate album in Photos, which you need to delete in the Photos app. You also need to remove recently deleted ones.
More suggestions.
For more declaring tips, be sure to read a separate article explaining how to free up space on our Mac properties and how to free up trash on your Mac. We also have tips on how to remove duplicate music on iTunes (or the music app).
We have an article explaining how to speed up a slow Mac and how to delete other storage on Mac, how to delete on Mac system and how to delete Mac cache.