My 5 year old MacBook recently started complaining about not having enough space. I don’t keep any music on my computer, and I have relatively few pictures. If I go to the About This Mac menu, and click on the Storage tab, the primary culprit is the System type. It takes up over 300 GB of my 500GB hard drive!
If you’ve been developing mobile apps for a few years on the same computer, I suspect you also have a glut of these opaque system files on your machine. Unlike pictures and music, it’s not so obvious how to clean them up. First, we have to identify what these files are, and then we need to figure out a safe way to dispose of them. Be advised that these files reside in the infamous Library folder. Apple hid it for a reason, so be careful!
Navigating the Library Folder
If you’re a developer, you’re probably accustomed to opening the Library folder every once in a while. Just in case you’ve forgotten how to get there, open up a Finder window, hold down the option key, and click on the Go menu at the top. Holding down the option key reveals the Library folder. Go ahead and click it.
From here, you can right click any of the folders inside and click Get Info. That will show you how much space each item takes up. As a mobile developer, Xcode and Android Studio are going to be the primary targets for the purge. Feel free to look around and see if you have any other massive file hoards, but we’ll be focusing on the Android and Developer folders.
Xcode Developers
Let’s start by dealing with our build-up of Xcode files. Navigate to Library/Developer/Xcode/iOS DeviceSupport. This folder is about 95 GB for me, and it contains symbol files dating back to iOS 6! This is more than a little unnecessary. Keep the folders for the iOS versions you still care about. You can safely delete everything in the folder for the other iOS versions. Even if you accidentally delete the support files for your favorite development device, Xcode will download the appropriate symbol files for that device again the next time you plug it in.
The other major storage hog in the Xcode environment is all of the old simulator data. Go to Library/Developer/CoreSimulator/Devices. I’ve got hundreds of old simulators in here, and they take up about 35 GB of space combined. To make things more complicated, their names are all lengthy strings of seemingly random letters and numbers. I have no easy way of knowing which ones are new and which ones are old.
Fortunately, Xcode tracks which simulators are no longer in use for your current Xcode version. Even better, we can purge them all it once through the Terminal. Open up Terminal and enter the command.
xcrun simctl delete unavailableYou’ll find a much shorter list of simulators in the Devices folder now. Mine take up less than 500 MB now! Between these two maneuvers, I’ve saved over 100 GB of space!
If you were to open Xcode now, you might find some problems. My storyboards turned black, and Xcode showed a vague error. We’re going to remedy this problem by deleting more files! Head over to Library/Developer/Xcode/DerivedData. This is a cache of files created when you build Xcode projects. You can safely delete everything in here. If you do happen to still get an Xcode error, clean your project, close Xcode, delete the DerivedData again, and restart your computer. You should be good as new!
There are other space saving options for Xcode, but they’re less meaningful and some are potentially more dangerous. For instance, you could delete some archives, but you might want them for debugging. I’m going to stop here for now, and call this a win on the Xcode front.
Android Developers
Space management on Android is a little more transparent than on Xcode. Considering you manually download which SDKs you want and create individual emulators for testing, you probably have a good idea of what’s taking up space here. Even so, sometimes it’s hard to know exactly how big an SDK or simulator actually is without looking it up. We’ll do that now.
Go to Library/Android/sdk/system-images. This has all of the Android SDKs that you’ve downloaded. Check the size on them. Mine are anywhere from 6 GB to 25 GB. Rather than deleting directly from here, I’ll use Android Studio. Click Configure from the opening dialog, and select SDK Manager. Delete SDKs that you don’t use for testing anymore, particularly if they’re exceptionally large.
Lastly, emulators aren’t going to take up as much space, but head over to the AVD Manager under the Tools menu. Delete the old devices you don’t use, and you’ll be awarded with a few free GB for your effort.
Conclusion
I’ve always enjoyed how Xcode downloads everything I need automatically compared to Android Studio forcing me to decide what I need. Of course, the downside is that Xcode will eventually take up a ton of space before you realize it. No worries! You can clean-up everything in a couple of minutes. If you waited as long as I did, you too may have 150 GB of new free space! So much room for activities!