Did you know that every major iOS simulator runtime downloaded through Xcode consumes between 8 GB and 15 GB of uncompressed disk space? If you have been developing for more than two years, your Mac probably houses runtimes for iOS 16.0, iOS 16.4, iOS 17.2, and iOS 18.0. Unless you are actively testing backward compatibility on specific minor releases, those runtimes are wasting tens of gigabytes of expensive SSD storage.

Even worse: these simulator runtimes are not located in your user home folder! They live in /Library/Developer/CoreSimulator/Profiles/Runtimes, meaning standard user-cache cleaners completely miss them. Here is how to safely audit and delete them.

iOS Simulator Runtime Manager in MagicMacCleaner
Auditing simulator runtime sizes, device counts, and last used timestamps.

How to Check Installed Simulator Runtimes via Terminal

Apple provides the command-line utility simctl to inspect and manage simulator environments. Open Terminal and execute:

xcrun simctl runtime list -v

This command prints every installed iOS, watchOS, tvOS, and visionOS runtime image, along with its unique identifier (UUID), build version, and whether it is currently available to Xcode.

How to Delete an Obsolete Runtime

Once you identify an old runtime you no longer need (for example, an outdated iOS 16.2 runtime), copy its UUID and run:

xcrun simctl runtime delete <RUNTIME_UUID>

macOS will instantly reclaim the 12 GB+ image. Alternatively, if typing UUIDs into Terminal feels tedious, MagicMacCleaner provides a native graphical Simulator Runtime Manager that lists each runtime's exact physical footprint, number of paired devices, and last-used date, allowing one-click deletion.

Mobile Developer Workflow: Free Up Storage on Physical Test iPhones

While clearing Xcode caches, simulator runtimes, and build containers frees vital space on your Mac, physical iOS test devices rapidly become clogged with test builds, crash artifacts, diagnostic screen recordings, and QA screenshots. Keeping your physical testing hardware lean is essential for rapid on-device debugging and reliable deployment.

  • Clearly Smart Storage Cleaner: Compresses gigabyte-heavy bug report screen recordings, detects duplicate test media, and organizes cluttered contacts on development and personal iPhones.
  • Swipe Photo Cleaner: Quickly review and purge hundreds of UI test screenshots and demo bursts with effortless swipe-to-delete gestures.

Apple Ecosystem Dev Tip: Test Device Optimization

Low storage on connected iOS devices can cause Xcode wireless deployment timeouts and LLDB debugging failures. Regular on-device media cleanup prevents cryptic build deployment errors.