Xcode simulator runtimes: can you delete them on Mac?

Where it is

What it is

A simulator runtime is a full copy of iOS, watchOS, tvOS or visionOS that the Simulator boots. Xcode downloads each one as a disk image and mounts it under /Library/Developer/CoreSimulator/Volumes when it is needed. The images themselves are stored elsewhere under /Library/Developer/CoreSimulator, and on recent versions of Xcode in a system-managed location.

This is different from ~/Library/Developer/CoreSimulator in your home folder, which holds the simulator devices you created and their app data.

Runtimes pile up because every new Xcode brings new OS versions and the old ones stay installed. Deleting the files directly can leave Xcode with runtimes it lists but cannot use.

How big it gets

Each runtime is several GB, so a Mac with a few years of iOS versions installed can hold tens of GB.

How to shrink it the right way

1. Run the command below to list installed runtimes with their identifiers and sizes.
2. In Xcode, choose Xcode, then Settings, then Components. On older versions the tab is called Platforms.
3. Select a runtime you no longer need and delete it there.
4. From Terminal, xcrun simctl runtime delete followed by a runtime's identifier from the list removes that one.
5. Afterwards, run xcrun simctl delete unavailable to remove simulator devices that depended on runtimes you deleted.

xcrun simctl runtime list

What happens afterwards

Simulators for the removed OS version are no longer available. If you need that version again, download it from the same Components tab in Xcode. It is a large download.

How Diskzy handles it

Diskzy shows the space simulator runtimes take on the disk map. Removing them is done through Xcode, which keeps its own records in step.

Related guides

• CoreSimulator Devices~/Library/Developer/CoreSimulator/Devices
• CoreSimulator Caches~/Library/Developer/CoreSimulator/Caches
• iOS DeviceSupport~/Library/Developer/Xcode/iOS DeviceSupport
• DerivedData~/Library/Developer/Xcode/DerivedData