How to optimize storage on Mac: The complete step-by-step guide

The days when Apple considered 128GB a reasonable amount of storage for a Mac are thankfully in the past – even the entry-level MacBook Neo has 256GB. But even so, most of us struggle with having enough space. That SSD fills up faster than any of us expect. Even when you optimize it by, say, storing your photos in iCloud and only keeping low-res previews on your Mac, the SSD seems to run out of free space all too quickly. In this article, we’ll show you how to optimize storage on your Mac by pruning all the files you don’t need and keeping those you do.

How to check storage on your Mac

Before you start trying to optimize storage on your Mac, you need to know how much you have available now, so that you know how much you’ve cleared when you’re finished. You could just open a new Finder window, select Macintosh HD, and look at the number at the bottom of the Finder window. But, while that will tell you how much space is available, it doesn’t help you understand where the rest has gone. To do that, you need to check System Settings.

1. Click the Apple menu and choose System Settings.
2. Go to General > Storage.
3. Check the color-coded meter at the top of the window to see the different categories of files that are taking up the most space.
4. To learn more about each category, click the ‘i’ next to it further down the window. Some categories will just explain what the category is, while others will allow to display the files in that category.

Follow the steps above, and you’ll have a good idea of where your storage space has gone, but not all the categories are well-explained. For example, Documents includes all files generated by applications on your Mac, including movies, audio files, zip archives, and Photoshop documents. System Data is a catch-all for files used by macOS and the applications you have installed.

How to use macOS’ built-in Optimize Storage tools

At the top of the Storage section of System Settings, you’ll see recommendations. For example, on my Mac, they were Store in iCloud and Empty Trash Automatically. You may see different recommendations. If you want to follow a recommendation, just click the button next to it.

• Store in iCloud synchronizes the contents of your Desktop and Documents folders with iCloud, and when you run short of storage, it keeps only the most recently opened files on your Mac. You can then download others when you need them.
• Empty Trash Automatically clears files out of your Trash when they’ve been there for 30 days.
• Optimize Storage automatically removes Apple TV movies and TV shows you’ve already viewed from your Mac.

After that, you should go through the list underneath the recommendations (sadly, organized alphabetically rather than by the amount of space each occupies) and click the ‘i’ next to it. Depending on the category, you may be able to see individual files. Documents, Books, Messages, and Podcasts all allow you to do that. You can then click the Size column to order the files by the amount of space they occupy, or the Last Opened column to order them by the date you last used them. To delete a file, select it (Command-click for multiple files) and click Delete.

Free up space manually — high-impact steps

Once you’ve exhausted all the recommendations and opportunities in System Settings > Storage, you’re into the weeds of removing files manually to save space. Here are some ideas for making the biggest impact with that.

1. Delete large and old files

Open a Finder window and choose a folder where you suspect there are files that you can move or delete. Click the View menu at the top of the window and choose ‘as List.’ To order files by size, click the top of the Size column. You should now see the largest files in the folder at the top of the list. To order by the last time the file was opened, click the top of the Date Modified column. Once you’ve got the files ordered the way you want them, you can move the largest or oldest to another disk or to the Trash.

As you can see, deleting large and old files manually takes a lot of time and effort, and there’s always a chance you will miss some. But there is an easier way: CleanMyMac’s My Clutter feature scans your Mac, looking for the largest and oldest files, and makes it easy to review them and then delete the ones you want to get rid of with a couple of clicks.

1. Start your free CleanMyMac trial — you can test it for 7 days first.
2. Choose My Clutter and click Scan.
3. Review its findings by category.
4. Click Remove.

2. Remove unused apps

We all have apps on our Mac that we don’t use anymore. And, together, they can take up several gigabytes or even tens of gigabytes of space. So, removing the ones you don’t use is an easy way to save space. However, to remove an app completely, it’s not enough to send the app binary from the Applications folder to the Trash — you need to get rid of all the other files it has stored in your Mac’s Library folder or your user Library folder.

The way to do that is to go to Finder, click the Go menu > Go to Folder. Then, type a file path, go to that location, and check for files from the app. Here are some common file paths you can check:
~/Library/Application Support
~/Library/Logs
~/Library/Preferences
~/Library/Caches

Those are the user Library versions of the folder paths (that’s what the ~ means). To check the main Library, use the same paths without the ~.

3. Clear your Downloads

This is an easy one. We all download things and then never do anything with them, leaving them to take up space. Open your Downloads folder, review its contents, and delete anything you don’t need.

4. Delete duplicate files and similar photo

If you have lots of files on your Mac that are duplicates of each other, they are taking up space unnecessarily. And if you have lots of similar photos, those are taking up space, too. The solution is to get rid of duplicates and review the similar photos, choose one, and delete the rest.

As with removing large and old files manually, deleting duplicates and similar images is time-consuming and laborious. Luckily, CleanMyMac’s My Clutter also identifies and removes these duplicates and similar images, at the same time as large and old files.

5. Clear system and browser caches

Clearing browser cache is straightforward. In Safari, go to Safari > Settings > Privacy > Manage Website Data and choose Remove all. You can also go to Settings > Advanced, check Show features for developers, then click the Develop menu and choose Empty cache.

In most other browsers, you can find the setting for emptying cache in the browser settings window under Privacy & Security.

System cache needs to be treated with more care. Deleting the wrong files can cause problems for your Mac. System cache is stored in ~/Library/Caches, but you should only remove files you know you won’t need, such as those associated with applications no longer on your Mac or that you don’t use.

6. Manage Time Machine snapshots and system data

APFS volumes on your Mac create snapshots – read-only copies of the parent volume – which can take up space. You can view these and delete them if you need to in Disk Utility.

1. Open Disk Utility, click the View menu, and choose Show APFS snapshots.
2. Choose a volume in the Disk Utility sidebar.
3. At the bottom of the window, you’ll see a list of snapshots, including Time Machine snapshots. Only if you have set up Time Machine, of course.
4. To delete one, select it and click the ‘-’ underneath it.

The faster way: use CleanMyMac

We’ve already shown you how CleanMyMac can help remove large and old files, duplicates, and similar images. But it can do a lot more than that. In fact, it can help with every one of the suggestions above. Best of all, it does all that with a single scan in its Cleanup feature. It scans your entire Mac for junk files, like system caches, app leftovers, language files you'll never use, mail attachments, and more. And it shows what it’s found before it deletes anything, so you’re always in control. If you decide to follow its recommendations, it takes only one click to delete everything and optimize storage on your Mac.

1. Open CleanMyMac.
2. Choose Cleanup.
3. Click Scan.
4. Review the results and click Clean.

You can also use the Performance feature to thin Time Machine snapshots so that you do not have to use Disk Utility.

Manual methods vs CleanMyMac compared

Key takeaways: How to keep storage optimized long-term

Now that you’ve optimized storage on your Mac, it’s important to keep it optimized. Here’s a checklist to keep you on track.

• Empty the Trash regularly.
• Scan with CleanMyMac’s Cleanup feature once a month.
• Monitor what is syncing with iCloud in System Settings > iCloud.
• Check recommendations in System Settings > General > Storage periodically.