Back in the days of hard drives we all had tons of space on our Macs, but SSDs are often more limited in capacity, and high-res video and other 'essential' files take up more storage than ever.

Running out of space can really hamper your computing: if you want your Mac to run smoothly you need to make sure you've got something like 10 percent of your storage free at all times. So in this article we walk you through simple steps that will help you free up space on your Mac.

You can also skip down to see the best software for clearing up your Mac.

How to manage storage using macOS

Back in 2016, with the launch of macOS Sierra, Apple introduced a new Optimized Storage feature that helps you delete old files or move things you don't need on your Mac over to the cloud. This feature is still available although changes in High Sierra and Mojave might have changed what you see there (for example, if you are using iCloud to store Desktop files, and iCloud Photo library for your photos, you won't see them here, but you might see a huge chunk of 'Other' or 'System'. We'll look in more detail at Other and System below.

Should you be running out of storage, you will keep seeing alerts with a link to your storage preferences where you can manage your storage. To access this section without this direct link, follow these steps:

  1. Click on the Apple logo in the top left of your screen and choose About This Mac.
  2. Next, click the Storage tab. This will show you how much storage you have available and how it's used. You'll see a bar which indicates how much space is given to Photos, System, Apps, Mail, and so on. This has changed slightly in later versions of macOS because now so much content can be stored in iCloud.
    Here's how this looked for us back when we were running Sierra. Back then we have more than 92GB of photos on our 121GB drive, and 738MB of purgeable stuff.

    How to free space on a Mac: macOS Sierra

    And now we are running Mojave, our photos are mostly in iCloud, as are the majority of our files and everything on our Desktop. As a result the storage on our Mac is predominantly given to Apps (red, 16.61GB), Photos (yellow, 5.17GB), iTunes (purple, 2.29GB), Mail (dark blue, 1GB) and Music Creation (light blue 1GB). The big chunk here is System 47.7GB. There's also just over 15GB given to a second volume that we called Test (a sort of partition where we are running beta software - here's how we made a partition/volume on our Mac).
  3. If you are running any version of macOS since Sierra (so, 10.14, 10.13, or 10.12), click on the Manage button. This will open another pane in which you're given four options: Store in iCloud, Optimize Storage, Empty Trash Automatically, and Reduce Clutter. You will also see a number of tabs on the left hand side of the window for Applications, Documents, GarageBand, iCloud Drive, Mail, Photos and Trash. Here's how that looks in Mojave:Mohave storage
  4. On a more populated Mac you will also see tabs for iOS Files - which is helpful as if you back up your iPhone or iPad to your Mac (or you have in the past) you may find loads of iOS apps lucking - none of which you need to keep as you can easily download any you have previously paid for. iOS apps can take up a lot of space so you could quickly win back some storage space this way.
  5. You'll also see iTunes here which will be populated with any music you store on your Mac - which could take up tons of GB if you don't subscribe to Apple Music or iTunes Match to keep your music in the cloud. Here's how our system looked back in Sierra before we were storing files in iCloud:

    How to free space on a Mac: Recommendations

  6. You can click on any of these options on the left to see more information about those file types. Click back on the Recommendations tab at the top of the list on the left and you'll be taken back to the options.

We will look at each step in turn.

Store in iCloud

Store in iCloud gives you the option of storing files in iCloud, for a price. Apple gives users 5GB of iCloud storage for free, but that's not really going to help you here. The prices for iCloud storage are as follows:

  • 5GB: free
  • 50GB: 79p/99c a month
  • 200GB: £2.49/$2.99 a month
  • 2TB: £6.99/$9.99 a month

Since macOS Siera it's been possible to share your Desktop and Documents in iCloud. This makes it really easy to sync files across multiple Macs. Essentially you can take your Desktop with you and access it on any Mac you own (and you can also access any file stored there from your iPhone or iPad.) Pages, Numbers, and other documents can also be saved in iCloud in folders associated with those apps.

These days you could have very little actually stored on your Mac and lots stored in iCloud.

Turn on Store in iCloud and it will start storing files, photos and messges in iCloud. 

Optimise Storage automatically

This option will delete TV shows or films that you've watched; it will also remove old email attachments. You needn't be afraid of losing either of these things because the emails will still be stored on the iCloud server anyway, and the shows you had purchased from iTunes can always be downloaded again for free.

All you need to do is click on Optimise and the Mac will do the work for you.

Empty Trash Automatically

Choose this option and macOS will empty files out of your Trash after they have been there for 30 days. Click Turn On… and you will see an alert asking if you're sure you want to erase Trash automatically. It should be pretty safe as 30 days is a long time to realise you didn't mean to delete something, so we recommend you click Turn On.

How to free space on a Mac: Empty trash automatically

Reduce Clutter

Reduce Clutter will review the content of your Mac and delete older documents.

Click on Review Files and you will be taken to a pane that shows Large Files, Downloads and a File Browser. We don't have many files on our MacBook Pro because we store most of them on iCloud, but if we did we'd be able to see the largest files on our Mac, including when we accessed them last and their size.

Click on the magnifying glass icon to see a preview of the file, and click on the X to delete it.

How to free space on a Mac: Reduce clutter

Other steps you can take to get more space on your Mac

Those are the steps that Apple now offers to help you better manage your storage space. Probably the biggest is the ability to store a vast majority of the things you would have once had on your Mac in the cloud.

Use iCloud Photo Library

The benefit of using iCloud Photo Library is that any photos you upload to your Mac in the future also appear on your other devices: iPhone, iPad and so on.

Given that our Photo library (prior to turning on iCloud Photo Library) was 96GB we started off by paying for the 200GB of space Apple offers. Months later we had upgraded to the full 2TB as we were storing all our documents, desktop, photos and more in iCloud.

  1. You might have turned on iCloud Photo Libary above, but if you haven't already you could do so in the Photos app. Go to Photos > Preferences.
  2. Check the box beside iCloud Photos.
  3. Select Optimise Mac Storage to make sure that your full-resolution photos are replaced with low-res versions (you can always download the full-res version if you need it).

With that setting your library should eventually shrink as the high res versions of your images are switched for low-res versions. But note that you will also get low res versions of all the images you have on all of your devices, so it's possible that you may not save a lot of space.

Beware that storing photos and videos in iCloud doesn't mean that they will automatically disappear from your Mac.

Also, beware that even if you are using iCloud Photo Library if you delete the photos from your Mac they will be deleted from iCloud too, iCloud is not a way to back up your photos so that you can delete them from your Mac.

If you want to remove your photo library to free up space look at our next suggestion.

Move photos to external storage

A better solution would be to free up space on your Mac by moving your photo library to an external hard drive. Read about how to move your photo library from your Mac to an external drive here.

To summarise, this is how to move your Photos library to an external drive:

  1. Quit Photos.
  2. Copy your Photos Library to an external drive. (To save having to delete them again afterwards, press the Cmd key when you drag the files over so that they are moved, with the original files automatically deleted, rather than copied.)
  3. Once the files have finished copying, hold down the Option/Alt key while starting up Photos.
  4. In Photos select Photos > Preferences and in General choose Use as System Photo Library.
  5. If you have iCloud Photo Library enabled, the Mac may get busy as it works out which photos reside in iCloud, but if should eventually complete without requiring a massive data transfer.

Remove photos

If you don't have a spare hard drive, you could just do some pruning or your photo library.

If you're anything like us you probably take a dozen photos for each photo you actually choose to put in an album or share on Facebook. Once in a while it's worth taking some time to delete these extra unneeded shots. If you haven't done this from time to time spending some time now is probably a good idea, even if you intend to just copy over your entire Photo library to an external drive or to start using iCloud Photo Library (both of which are covered in detail above).

Here's another tip: If you've been a Mac user for some time and at one point migrated to the Photos app from iPhoto or Aperture (or both applications), you may find that there are files created by Aperture and iPhoto still lurking on your Mac. Both those apps stored their libraries in a single file, located in Pictures in your user directory.

When you migrated to Photos from Aperture or iPhoto, the old library files remain in your Pictures folder, meaning you now have a Photos library and an Aperture or iPhoto library. If you never plan to use Aperture or iPhoto again, you can get rid of their libraries, but we'd recommend archiving them on an external hard drive just in case (Note, there can be some confusion about your photo library in Photos and iPhoto - the apps are accessing the same images, so your whole library isn't duplicated, but there are associated files that you no longer need).

We had a 6GB iPhoto file on our Mac. Right click on it to 'Show package contents' and remove all bar the Masters file.

Crop iTunes

Your iTunes library might be another candidate for re-claiming disk space, especially if you spent a lot of time importing your CDs many years ago. If your iTunes library holds a few GB worth of music you have a few options.

You can copy the whole thing from your Music directory to an external hard drive and point iTunes to it from its Preferences. That's great if your Mac is a desktop model, but not ideal if it's a notebook. We have a tutorial on how to move your iTunes library to an external hard drive here.

You could use a NAS box instead of an external hard drive in that instance, so that you can access your music whenever you're connected to your local network.

Another option is to pay £21.99/year to subscribe to iTunes Match. Here's how to set up iTunes Match.

Once you've set it up, iTunes Match allows you to access all the music in your iTunes Library on Apple's servers, meaning you don't have to have it stored locally at all. You'll need to be connected to the internet in order to play music, but other than that, it's just like using iTunes with locally stored music.

And, as a bonus, if you decide at a later date that you want to download your music from iTunes Match, you get 256-bit AAC files which are probably of better quality than the ones you had stored on your Mac.

How to free space on a Mac: Downloads

The final option here is to subscribe to Apple Music, Apple's service that for £9.99 a month gives you access to its whole music library, so assuming that all the music you enjoy is on iTunes you can delete all your music from your Mac and just stream the music from Apple Music instead.

If at a later date you decide not to subscribe anymore, you will always be able to download for free any tracks you bought from the iTunes Music Store before you took out the subscription, but note that unless you have iTunes Match you won't be able to download tracks that you uploaded to your iTunes library yourself, so don't throw out those CDs just yet.

Remove files from your Downloads folder

Your Downloads folder also probably houses large files you know longer need. If you download large PDFs, images, or disk image files and don't prune Downloads regularly, it's probably full of stuff you don't need. Start with disk images. If you've installed their contents, you won't need them anymore. If they contain apps, you should always install the latest version anyway.

Find out which apps are hogging space

Once you've dealt with the obvious culprits, it's time to go deeper and find the other disk hogs. There are several apps that will show you which files are taking up big chunks of disk space, or allow you to order files in the Finder based on their size.

GrandPerspective (free) or from the Mac App Store for £1.99 here and DaisyDisk (£9.99/$9.99, buy it here) give good visual indications while OmniDiskSweeper (free) uses the standard hierarchical file window to show the sizes of every file and folder. Other apps such as CleanMyMac 2 (£34.95) show disk usage as part of their cleanup features. Parallels Toolbox also has a Clean Drive tool along with lots of other usefuol tools (for £15.99 a year).

How to free space on a Mac: Space-hogging apps

See what files are taking up most space for free

You can also do it easily without an app.

  1. Open a new Finder window and navigate to your Home folder, or press Shift-Cmd-H from the Finder.
  2. Press Cmd-F to open a new Find window and in the first dropdown menu under Search (it might say Kind), choose Other.
  3. From the window that opens next, scroll down until you see File Size, and check the box next to it. You have now selected that as the attribute for a search.
  4. In the next dropdown menu choose 'greater than', and change the file size units to MB. Now type in a file size, say 100, to display all the files in your Home folder that are bigger than 100MB.
  5. You can now choose which files to delete or archive on an external disk, and free up disk space quickly.

We also have advice about how to find duplicate files here.

Empty the trash frequently

If you decided not to Empty Trash Automatically as per Apple's advice above, make sure that you Empty the Trash frequently.

If there are any stubborn files that won't disappear, the easiest solution is to use Trash It! (free), a useful one-trick pony.

Delete attachments from Mail

How about your Mail attachments folder? Think about how many emails you receive with large attachments. What happens to these? Within the main Mail folder (~/Library/Mail), attachments for incoming mail are stored in the inbox folder.

To make sure those from deleted emails are removed, go to 'Remove unedited downloads' in Mail's preferences and select 'After Message is Deleted'.

The current version of Mail also stores attachments in ~/Library/Containers/com.apple.mail/Data/Mail Downloads. As long as you don't need them these can also be deleted, often saving you many hundreds of MB.

Remove duplicate files

Identifying and dumping duplicate files is another good way of freeing up disk space. Gemini costs £15.95 on the Mac App Store (in the US you can buy it on the Mac Store for $19.99) and allows you to scan your Mac for duplicate files so you can dump one copy.

How to free space on a Mac: Gemini

How much of your precious hard drive space is being taken up by duplicate files? While hard drives may be getting bigger and cheaper, Apple's direction is that of smaller, faster SSD drives. The problem is that these have smaller capacities so a higher level of filing discipline is essential.

There are a number of reasons why you end up with so many dupe files. When you add songs to iTunes, if you have 'Copy files to iTunes Media folder when adding to library' checked in the preferences, you keep the original. Instant duplication. A couple of thousand high quality songs and that's anything up to 10GB hard drive space wasted. And that doesn't include dupes within iTunes.

If you use Apple Mail, remember that all attachments reside in Mail's own download folder. This can be another source of duplication.

More generic apps use various strategies and criteria to find duplicates and give you control over which ones to get rid of. Have a look at Tidy Up ($29.99) or Singlemizer (£9.99/$9.99 on the Mac App Store).

Quit apps running in the background

Quitting apps that have been open for several days or more, or even restarting your Mac completely on a regular basis, will also help free up disk space.

Applications create temporary files to store data and the longer they run without quitting, the bigger those files become. When you quit the app, the cache files are deleted and the disk space returned.

Get rid of unwanted Mac apps

It's amazing how quickly you acquire apps, and the space they eat up can be horrifying.

Most macOS apps are bundles. The application is usually a special folder that looks like a single, double-clickable file and contains almost all the files needed to run the app.

Trashing the app is easy; getting rid of all the support files isn't. There are preferences (plist) and application support files and these can exist in a number of places on your Mac. These files along with the app itself may be wasting many gigabytes of your hard drive space.

Some major apps include an uninstaller. For example, you'll find one of these in the Additional Tools folder of Microsoft Office. Sometimes an app's installer doubles as an uninstaller. But the lack of a dedicated uninstaller in macOS is a serious omission.

Fortunately there are a number of third-party options. AppCleaner (free, download from the Mac App Store here), AppDelete ($7.99) and AppZapper ($12.95) all do the same job - but the fact that they each find different files to remove shows how complicated a process uninstalling can be!

Remove extra languages you don't need

macOS supports a range of languages, being localised for more than 25 languages all of which are included automatically during installation. Go to System Preferences > Language & Region; here languages can be put into preferred order making it easy to switch between them.

Many major applications support multiple languages too, using the order from Language & Text to select one if the app doesn't support your main language. The problem is that if you only want to use one or two languages, macOS and many of your apps are bloated with all the others.

If you want to delete extra language files that you know you won't be needing, go to the Resources folder and look for folders ending in .lproj. Each of those folders will include a language file. You should be able to trash these folders without any problems.

Remove unwanted code

Getting rid of unwanted code is another disk-saving exercise.

Monolingual (donation requested) lets you remove specific architectures from macOS along with specific languages. While it can claw back huge swathes of hard drive space, it can also render your Mac unbootable if you're not careful. Use with caution.

How to free space on a Mac: Monolingual

Use cloud storage space

We've discussed iCloud already, but there are other cloud storage options.

Cloud storage services are great for making files available remotely, but they can also take up space on your Mac. Both Dropbox and OneDrive, for example, sync everything you store in them with your Mac by default - assuming you've installed the Dropbox/ OneDrive app.

If you only have the default 2GB storage available for free from Dropbox, that's not too much of a problem. But Microsoft gives Office 365 subscribers 1TB of space free, so if you use that to store lots of files, you could find yourself running out of disk space very quickly. The same is true if you pay for more space on Dropbox.

In both cases, however, you can choose to sync only files and folders you specify.

In Dropbox, click on the menu bar item, then click the cog and then Preferences. Click the Account tab, then click Change Settings. Now untick the files and folders you don't want to sync with your Mac.

In OneDrive, click the menu bar item, then Preferences. Click Choose Folders, then Choose Folders, then Choose Folders to sync. Untick folders, or click the expand arrow to access individual files and untick those.

An alternative would be to sign up for more iCloud storage, as we mentioned earlier.

I really need to keep everything!

You might be thinking I need the space, but I don't want to delete anything! If you really are the proverbial data squirrel, here are a few simple suggestions:

  • Archive any files you're unlikely to need regularly. Ctrl-click on a folder and select the compress option. (Here's more info on how to zip Mac files.) The space saved will vary according to the type of file being archived: JPEGs and DMGs, for instance, are unlikely to compress very much. Once created, archives can either remain on your Mac or be saved to an external drive.
  • Use an external drive for data files. This would be especially useful for design, audio or video files.
  • Migrate your iTunes Music folder to an external drive and then relink to this within iTunes. This is quite possibly the single largest folder on your Mac: ours is a disk-busting 25GB.

Finally, if you do take the decision to delete files or folders, always back them up first.