Running Low on Space on Your Mac? Here’s How to Clear Unnecessary Data

SSDs are great—they’re fast, durable, and reliable—but they’re also expensive, which results in many of us not having as much storage built into our Macs as we’d like, especially if you didn’t choose to upgrade the storage when you bought your Mac, or for those who download videos in iTunes or take a lot of photos.

But Apple has a built-in tool for cleaning house: Storage Management. It’s a feature that was introduced a few years ago, but few people even know it exists.

To launch Storage Management, click the Apple logo > About This Mac, click the Storage tab, and then click Manage… but wait! Before you click Manage, look at the About This Mac window’s Storage view.

Hover over each colored bar to see how much space is taken up by a particular type of data. The white space at the end of the bar shows space that’s still available. The grey “System” data can be a myriad of things from settings files to application database files. It’s kind of a catch-all. The hashed “Purgeable” section includes caches and trash files, anything that the computer is willing to delete should you need space for something else. You can’t do much here, but the view gives you a quick overview of your usage.

When you click Manage, System Information launches, and the Storage Management window appears. (You can also open System Information manually and choose Window > Storage Management.) In the sidebar at the left, ignore Recommendations and look at the rest of the categories, particularly Applications, Documents, and iOS Files. The specific categories will vary a bit between Macs, depending on what apps you use, but they correspond to the colored bars you saw in the About This Mac window’s Storage view.


The Applications category lists your apps and is sorted by size by default. But try clicking the column header for Kind and scrolling down. You can probably trash most apps tagged as Duplicates or Older Versions. Similarly, click the Last Accessed column header to see which apps you haven’t launched in years. Many of them can probably go. Plus, you can redownload anything tagged as coming from the App Store should you need them in the future, so you can toss those apps to save space. And consider throwing away anything that starts with “Install macOS” or “Install OS X”. Those are system installers for Apple’s annual software upgrades. Many of which may be old, and any can be downloaded again if you do need to do the upgrade in the future.

One thing to be aware of, this does not delete settings files for the app or anything it sticks in other places of the computer. To fully remove the apps I recommend a utility such as the free AppCleaner. It will dig around your computer looking for any related files. These extra files typically don’t use up too much storage space, but they can add to clutter and other problems.


In Documents, you’ll see three tabs: Large Files, Downloads, and File Browser.

  • Large Files focuses on files over 50 MB in size, ordered by size.
  • Downloads displays the contents of your Downloads folder (much of which you likely don’t need once you’ve installed the software or looked at the document).
  • File Browser gives you a column view that’s sorted by file size and shows sizes next to each item, including folders. It’s great for trawling through your drive to see what’s consuming all that space.

In any of these views other than File Browser, hover over any item to see an X button for deleting the file and a magnifying glass button that reveals the file in the Finder. Click a file once and press the spacebar to see a preview of the file.

In File Browser, select one or more files and either drag them to the Trash icon in the Dock, or press Command-Delete on your keyboard.

iOS Files

If you’ve used iTunes to manage iOS devices in the past, pay special attention to the iOS Files category. It shows any device backups and software updates that are stored on your Mac’s drive. If you still use iTunes to back up your device, it’s worth keeping the latest backup of devices you still use, but many people have obsolete backups and unnecessary updates kicking around.


As noted before, the rest of the categories here may vary depending on what apps you use. With Books and iTunes, you can remove content that you’ve purchased since you can download it again. With Mail and Photos, Storage Management merely tells you how much space the app’s data occupies and lets you enable space optimization (downloading only recent attachments for Mail, and keeping only optimized photos on the Mac). Do be careful with using options to optimize your storage. If you do that many of your files will no longer be on your computer which means they no longer get backed up in Time Machine. For this reason, I always recommend that you don’t use these options unless you have another computer that does have everything stored locally with a Time Machine backup.

If your Mac’s drive is filling up—if it has less than 10 percent free space—consider using the Storage Management tools to search out and delete files that are wasting space. To be safe, make a backup first, which you are doing already, right?

Install the latest software updates. If you’ve been putting off the latest software updates chances are that they are sitting on your computer taking up space waiting to be installed. Even the smaller bug fix updates can take up a significant amount of storage, which will clear out once the update is installed. Go to the Apple menu > System Preferences > Software Update. If you are not on the latest system software an upgrade will be offered there. If you aren’t ready for that jump you should at least install the bug fix updates for the version of the system software you are currently on. Do that by clicking the “More info” link under the other update section.

Other Solutions

Empty your trash. This is something people often forget to do. By default your Mac keeps everything you delete until you ask it to be purged. To do that, click and hold the Trash icon on your dock and choose “Empty Trash”. If you are forgetful you can set your Mac to automatically purge anything that has been in your trash for 30 days.

There are plenty of programs out there that say they will reclaim storage. The problem is, it’s hard to know which ones are legitimate and which ones are malware or won’t find any more than the built-in tool I showed you above. Here are some additional solutions including some third party ones that I like.

MacPaw’s CleanMyMac X is a great solution for those who don’t mind its $35 price tag (and don’t mind upgrading when a new version comes out–you don’t want to be running a cleaning utility that’s designed for an old system software). This utility can help you identify and remove unnecessary data to free up space. It can ferret out forgotten downloads, old videos, mammoth folders, bloated caches, outdated iOS updates and backups, copies of iOS apps, and more. It also boasts other features that can improve performance, protect your Mac from malware, and keep your apps up to date.

Daisy Disk ($9.99) is great for getting a comprehensive overview of your storage usage. It won’t give you advice about what to delete, it simply gives you a graphical overview of your drive and tells you what folders and files are using up space. This is useful for finding things you didn’t know existed like old system software or database files for long-gone applications, but it really does take some knowledge to understand what you are looking at. It’s particularly good at finding the things in the mysterious “System” section.

Price: $9.99
  • ‎DaisyDisk Screenshot
  • ‎DaisyDisk Screenshot
  • ‎DaisyDisk Screenshot
  • ‎DaisyDisk Screenshot
  • ‎DaisyDisk Screenshot
  • ‎DaisyDisk Screenshot

Gemini 2 works really well if your problem is duplicate files. Let it scan your drive (or even attach external drives and it will look for duplicates among your drives) and it will easily find identical files and folders. It will even find photos that are similar and offer to keep your favorite.

Dropbox Smart Sync. Dropbox, in general, does not save space on your computer, a common misconception. When you put files into Dropbox they do not get moved off of your computer into the cloud. They get synced to the cloud. Your computer still keeps a full copy of your files in the Dropbox folder. Deleting a file from your computer will delete it from your Dropbox account. There is, however, a new option for “Professional” and “Teams” level subscribers: Smart Sync. If you enable this feature you can control-click on any file or folder to keep it “online-only”. This keeps the icon on your computer, but the content gets removed. If you double-click the file to open it, a full copy will download and open. But now that it’s on your computer, you may want to control-click the file to return it to online-only again.

Get rid of things you simply don’t need. Do your files spark joy? If not, maybe it’s time to KonMari your computer. The biggest offenders to storage are usually videos, photos, and music, so start there. Emails and documents don’t typically take up much space. A single photograph takes up about as much space as several hundred emails that don’t have attachments. One place to get started for a lot of people is the “Videos” album in your Photos app. Open up your Photos app and look for the “Media Types” folder on the left column. Click the triangle next to it if it’s not expanded. Choose Videos and go through those. These videos can often take up an enormous amount of space since they are after all 30 pictures a second. You can also find a lot of large files in “Bursts” because those are many photos in one. Or use the “People” albums to start deleting photos of your exes. When you’re done, you can go to the “Recently Deleted” album to reclaim the space if you need it back right away, though you’re probably better off waiting a month for the pictures to clear themselves automatically in case you change your mind about any of them.

Back up with Time Machine. If you have Time Machine configured but you haven’t connected your drive in a while, you may be seeing a message pop up in the upper right corner of your Mac complaining that it’s been many days since your last backup. Recent versions of macOS will accumulate backups, waiting for you to plug in your drive before it offloads them and freeing up space. Go ahead and plug in your drive and let it do its magic. If you haven’t backed up in months it could take several hours to back up. So leave your drive connected overnight and if it’s a notebook computer leave the lid open with power connected.

Upgrade your storage, if the problem is simply that you need more than your computer has. This might work for iMac and Mac Pro. However, any MacBook or MacBook Pro since 2012 or any MacBook Air have integrated or proprietary storage, so the only real solution in those cases is to replace the computer with one that has what you need. This is why I always tell people to buy the computer you need for the next five or ten years, not the computer you need right now.

And of course, there is me! Whenever I visit clients I give their computers a good manual inspection to discover what things are eating up their storage. I use many of the same tools I mention above, but since I understand the ins and outs of what these tools do I can usually find much more than these tools will on their own.

What not to do

Don’t delete files from your computer assuming you have them in your iCloud account. iCloud is a syncing service, so deleting things from your computer deletes them from the cloud.

Don’t delete files from your computer assuming they are in Time Machine. If you are relying on Time Machine, then it’s no longer your backup; it’s your original. Your backup drive could go bad. If they didn’t then that’s the technology we would use in computers in the first place. And after your Time Machine drive fills up it will start removing old backups to make way for the new backups.

Don’t delete files from your computer assuming you have them in an online backup like Backblaze. Those services will remove files after you’ve removed them from your computer, usually after about a month.

Don’t move files to a thumb drive. Thumb drives are notorious at going bad, and there aren’t good diagnostic tools out there to find out when they do. They simply start working slow and then some of the files stop opening. Thumb drives are only good for shuffling large files between computers. Never use them for originals.

Don’t move files to an external drive unless you have a good backup system in place that you are checking regularly. External hard drives can go bad, too. And keeping them in the closet or a safety deposit box won’t protect them. It might last a little longer than under active use, but it will still eventually go bad.