If your Mac is starting to run slow the first thing to check is if you are running low on space. It’s generally advised that you should have 10% of your total space free on your Mac for the most optimum working. If you are down to your last few gigabytes then it’s time to do some housework and grab some space back.
Over time, a Mac is likely to accumulate a large collection of duplicate files that take up this valuable space so that’s 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 quicker ways to cleanse your system of these delinquent doppelgängers.
Why do I have duplicate files?
In most cases these will be mistaken downloads (caused by clicking on a link twice), Mail and Messages attachments, a convoluted filing system, a bad habit of dragging things to your desktop, or a number of other possibilities. Unless you’re an unusually fastidious Mac user, duplicates are going to turn up one way or another.
Is it possible to find duplicate files on Mac without using third-party software?
It is possible to search for and delete duplicate files in macOS, but macOS itself doesn’t have a duplicate file finder. You can however use Smart Folders in the Finder to locate files that are the same (or similar) and use features like Quick Look to help you decide whether to delete them. There is also a command you can use in Terminal, although we didn’t have much luck with that method. We’ll explain how both methods work below, as well as run through some of the easy to use third-party options.
How to find duplicates using the Finder
It is possible to locate duplicate files on your system by using the Smart Folders feature in the Finder.
- Start by opening the Finder.
- Navigate to File > New Smart Folder in the menu.
- Click on the ‘+’ button in the upper-right corner.
- Now choose what you want to search by to locate the duplicate files, e.g. Kind = Image or Kind = Document.
Now you can search for documents, photos, music, or several other files types. The key is how you sort the results. Ordering them by name should bring up any duplicates that are easy to spot. (If it’s not displayed in name order click on the drop-down menu to switch to List view).
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Just remember to check the date to see if it is a true duplicate – you don’t want to delete the wrong version of an important document, for example. (If you can’t see the date right right-click and choose Date Added, you can even add Date Last Opened to make sure you pick the right one to delete.
Another way to check is to click on the document or image and press the space bar to get a preview.
You can also check the location of the file you are thinking of deleting if you click to select the file and look at the bottom of the window. That might tell you if it’s the version you saved in the proper folder.
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While this method will work, it’s far from ideal. One issue could be that you have given the same file different names and this method will not show that up.
It’s also a time-consuming process and the time spent plowing through the long list of files could be better spent by visiting the App Store and buying software that will find and safely delete the duplicates for you instead.
Best duplicate file finders for Mac
Wondering if there are third-party applications recommended for finding duplicate files on a Mac? There are a number of duplicate file finders on the Mac App Store which will automatically search your system and recommend file doubles that can be removed.
Options include Nekony’s Duplicate File Finder, which offers a free version on the App Store, as well as paid upgrades. You could also try the Find Duplicates feature of Parallels Toolbox, which offers a functioning free trial for seven days, and we like Gemini 2 from MacPaw which has a three-day functioning trial. Read our reviews of Parallels Toolbox and Gemini 2.
Most apps offer similar features, in that you ask the app to scan your hard drive, then are presented with a list of duplicates, accompanied by the original file so you know which ones are safe to delete.
Usually you’ll have to move to a paid version for advanced features such as deleting duplicate folders, hidden files and similar functions.
1. Gemini 2
Pros
- Polished, intuitive user interface
- Accurate detection of exact matches
- One-time purchase option
Cons
- Game-style achievements are an unnecessary distraction
Price When Reviewed: From $19.95 for 1 Mac, annually Best Prices Today: $19.95 at MacPaw (annually)
One of our favourite duplicate removal apps, and one with a good level of positive feedback from customers, is Gemini 2, which starts at $19.95/£15.95 a year for one Mac, or a one-time purchase of $44.95/£39.95. While the name might be more in keeping with a dystopian sci-fi novel, the app is a powerful tool for your Mac.
Once you have granted permission to scan your folders Gemini 2 will go ahead and Scan for Duplicates. The scan of our 256GB drive (with about 150GB files) took about seven minutes. When the scan had finished it had turned up 12.63GB worth of duplicates.
Gemini 2 selected 45.6MB files automatically – these were duplicated photos. We were able to automatically delete these by clicking on Smart Cleanup.
However, there were still GBs of files left that were ripe for removal. It is possible to sort through the duplicates and choose which version to keep. Click on Select More to go through all of the duplicates that Gemini has found. You can flick through these and decide which ones you want to lose. It’s a bit of a drag that you have to do this manually, but it’s still easier, and more visual, than using the Finder. You can also choose to delete every instance of the file or photo if you really don’t need it.
Since we were removing photos Gemini reminded us that we need to also remove the photos from Recently Deleted in Photos, alternatively, we could wait 30 days for them to be removed automatically. You can review what was trashed and ‘Put back’ any files you have second thoughts about (but this step needs to be taken before you delete the contents of your Recently Deleted folder.)
Not only can Gemini find doubles of any files on your hard drive, but it also searches external drives and cloud storage services such as Google Drive and Dropbox. All this is accompanied by the ability to immediately replace any accidentally deleted files.
Find out more about Gemini – and the firm’s other related apps, such as CleanMyMac X – on MacPaw’s website.
Read our Gemini 2 review.
2. Duplicate File Finder
Pros
- Perpetual license available
- Free version available
Cons
- Slightly complex to use
Price When Reviewed: Free version, Pro version from $34.99 Best Prices Today: Free at Nektony
Nektony’s Duplicate File Finder can scan your Home folder, or you can choose a particular folder or drag files in. There are two versions of the software – a free and a Pro version. The latter adds a few extra features, such as the ability to merge folders, and restore removed duplicates. It starts at $14.95 (approx £12) a year from Nektony’s website, or the Pro version costs $29.50/£34.99 for one Mac from the Mac App Store. There is also a one-time purchase option for $69.90 (£56) which is currently reduced to $49.95 (£39.90).
You’ll need to grant it permission to scan various folders and sections of your Mac. The software will then scan for duplicates with some fancy graphs representing the kind of files it has found.
You can then click on the Cleanup Hints section to find some files to delete. At every step there is a detailed overlay showing you what to do. Just click on the x to remove it.
In each case, you can review the duplicate before deleting it. As with Gemini, you can remove the duplicates or you can remove all versions of the file or photo. The Review and Remove option does let you see a visual of where the duplicated file was located, which might be useful.
You can also choose Auto Select to pick the duplicates for you – you can even refine the selection. You get to review these before they are removed.
Duplicate File Finder creates a Duplicates album in Photos, which you will need to delete within the Photo app. You will also have to remove these from Recently Deleted.
3. Parallels Toolbox
Pros
- Offers lots of tools
- Really easy to use
Cons
- You can't buy it outright
Price When Reviewed: $24.99 per year, free 7-day trial Best Prices Today: $24.99 at Parallels (annually)
Parallels ToolBox has more than 50 useful tools that you can use to clear space and speed up your Mac and among these is an option that can search for and delete duplicate files.
The Clean Drive tool can locate unnecessary files that are taking up space on your Mac and find duplicate files that you may no longer need. There are many other tools that you may find useful, take a look at our full review of Parallels Toolbox to see what else you get.
There is no perpetual license option, so Toolbox requires an annual subscription of $24.99/£20.99 (unless you get it as part of Parallels Desktop) but you can take advantage of the 7-day trial.
Read our full Parallels Toolbox review
How to find duplicate files with Terminal
If you are feeling confident you could delete duplicate files using Terminal. You will still need to remove them manually, but it might simplify the hunt. Just beware that if you aren’t familiar with the Mac operating system you could accidentally delete files you need. So tread cautiously.
- Open Terminal (the quickest way to do this is to press Space + Command and start typing Terminal).
- Enter cd ~/[name of the folder you want to investigate]. e.g. cd ~/Documents
- Paste in: find ./ -type f -exec md5 {} \; | awk -F ‘=’ ‘{print $2 “\t” $1}’ | sort | tee duplicates.txt
- Press Return.
- In the Documents folder you will find a new text document including duplicates, if it finds any.
It took some time for Terminal to locate the duplicates in our Desktop file, but eventually, we had a list of files that were duplicates along with the location they could be found in It was then required that we locate and delete each of those files.
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FAQ
How accurate are duplicate file-finding tools on a Mac?
We found the tools we used to be accurate. One of the issues with finding duplicate files is that some files are named differently, but still duplicates. Using the Finder to locate these is a lot harder and can be time-consuming. We found that using a third party tool helped us identify these duplicates.
What should you do after finding duplicate files on Mac?
After you have located a file that can be deleted you need only drag it to the Trash (Bin). You can then empty the Trash by right-clicking on it and choosing Empty Bin.
Will deleting duplicate files affect my Mac’s performance?
If your Mac is running slowly because you are running out of space deleting duplicates and making more space will speed things up. Read: How to clear cache on a Mac to find out why deleting files from cache can speed things up.
More advice…
For more decluttering tips, be sure to read our How to free up space on a Mac feature, and a separate article that explains how to empty the Trash on your Mac. We also have advice about how to remove duplicated music in iTunes (or the Music app).
We also have this guide to ways to speed up a slow Mac and How to delete Other storage on the Mac, How to delete System on the Mac, and an article that explains How to delete cache on a Mac.
