I found that Xcode on my laptop consumes much of its storage, so I am trying to delete unnecessary files in Xcode.
There are four directories under Application/Xcode.app/Contents/Developer/Platforms/. I feel that WatchSimulator.platform and AppleTVSimulator.platform are not necessary, because I use Xcode almost only for basic iOS development.
I would like to know if I can delete those platforms directories directly?
Yes, you can delete any simulator that you don't use. I do this routinely when I stop supporting older iOS versions.
If you delete them and then you find that you need them at some point in the future, you can redownload them from Apple's developer site.
The best way to delete them is in Xcode. Go to Window -> Devices and Simulators. This will open a new window with all the devices you use in Xcode.
At the top, tap on Simulators and you'll see a list on the left-side.
From there, find the simulator you want to delete and Cntl - click (or right-click) and select Delete.
I do this with each simulator that runs in each iOS version that I no longer support.
Update July 2020: There's a free utility in the Mac App Store named DevCleaner for Xcode. This application can display and delete simulators and various caches. I've found it be a very quick and easy way to regain space. I'm not the developer or associated with this application in any way.
Xcode now shares the simulators with all users. So, you need to remove the simulators from the following folder:
/Library/Developer/CoreSimulator/Profiles/Runtimes
For example:
cd /Library/Developer/CoreSimulator/Profiles/Runtimes
sudo rm -rf iOS\ 8.4.simruntime/
sudo rm -rf iOS\ 9.3.simruntime/
Cheers!
You can easily remove all unavailable simulators with this command in the terminal:
xcrun simctl delete unavailable
$ open /Library/Developer/CoreSimulator/Profiles/Runtimes
For example: iOS 13.0, watchOS 6.0 These take the most space, by far. Each one can be up to ~5GB
$ open ~/Library/Developer/CoreSimulator/Devices
For example: iPhone Xr, iPhone 11 Pro Max. These are typically <15 mb each.
Simulators are split between runtimes and devices. If you run $ xcrun simctl list you can see an overview, but if you want to find the physical location of these simulators, look in these directories I've shown.
It's totally safe to delete runtimes you don't support. You can reinstall these later if you want.
Despite @fsb's answer allows to delete simulator "instances" the right way to free a massive space used by old simulator platforms not needed anymore is going to the following folder:
~/Library/Developer/Xcode/iOS DeviceSupport
and remove the folders corresponding to the simulator/platforms you don't need anymore.
Additionally, there is a very good article including this and other tips:
to list all simulator devices xcrun simctl list devices or xcrun simctl list --json
to delete all simulator devices xcrun simctl delete all
to delete a specific device xcrun simctl delete <device udid>
to remove old devices for runtimes that are no longer supported xcrun simctl delete unavailable
To delete simulators by iOS version:
If you only want to remove simulators for a specific version, and you happen to have fastlane installed, you can launch an interactive ruby shell and run the following commands to remove all iOS 10 simulators:
# launch the interactive ruby shell (irb)
$ irb
# require the device manager capabilities of fastlane core
irb(main):001:0> require 'fastlane_core/device_manager'
# delete all iOS 10 simulators
irb(main):002:0> FastlaneCore::Simulator.delete_all_by_version(os_version: "10.0")
In newer versions of macOS (e.g. macOS 13 - Ventura), you can clean up a lot of Xcode and Device Support files via "System Settings" (Preferences).
I was able to free up a lot more space using this Settings page. Just before I did this, I had run @beryllium's answer (i.e. "xcrun simctl delete unavailable" in Terminal), which also cleaned up a lot of disk space, so I'm not sure if the Settings page would have cleaned up those files too. To be sure, I'd recommend also running "xcrun simctl delete unavailable" in the terminal, after the steps above, to see if it frees up more.
For reference, I was able to clean up another 53 GB using the Storage settings page, after I had already cleaned up all the unneeded files under ~/Library/Developer/CoreSimulator/Devices using xcrun.
Beside the regular simulator devices in the known location (~/Library/Developer/CoreSimulator/Devices/), Xcode now creates automatically simulator devices "behind your back" for SwiftUI previews, Interface Builder, Playgrounds and Parallel Testing. They also might take up some space after a while.
So it might be useful to delete them all using the commands below:
xcrun simctl --set playgrounds delete all
xcrun simctl --set previews delete all
xcrun simctl --set interfacebuilder delete all
xcrun simctl --set testing delete all
Most of the disk space is used by just one subfolder under each *.platform folder inside Xcode.app, Library/Developer/CoreSimulator/Profiles/Runtimes (so eg /Applications/Xcode.app/Contents/Developer/Platforms/AppleTVOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes).
If you just delete the *.platform folders then Xcode crashes a few seconds after launching, but removing just the Runtimes subfolder under them seems to be OK - for the version I have at least, 13.4.1.
I did this:
backup=~/xcode-smallen
subfolder=Library/Developer/CoreSimulator/Profiles/Runtimes
for f in /Applications/Xcode.app/Contents/Developer/Platforms/AppleTVOS.platform /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform /Applications/Xcode.app/Contents/Developer/Platforms/WatchOS.platform ; do
platform=`basename $f`
target=$backup/$platform/$subfolder
mkdir -p $target
mv $f/$subfolder $target
done
and Xcode now only needs 11GB (7GB compressed) and it still launches and compiles projects just fine. So this seems to be the ticket for now.
lsin Terminal lacks a flag to see a file is using hfsCompression, sans the Get Info Sheet where you can see the on disk value is dramatically different then the size show in bytes. There is a utility written by a third party, which includes the source code if one wants to compile it themselves, afsctool. Among its capabilities is to get information about existing HFS+ compressed file(s).