TidyMacRun xcrun simctl delete unavailable. It removes only simulators your current Xcode can no longer use, which is where most of the wasted space in ~/Library/Developer/CoreSimulator comes from. Working simulators may hold test data, so check before removing those.
The five questions
Virtual iPhones and iPads Xcode uses to test apps.
Each simulator keeps its own apps and data, and old ones stay behind after Xcode updates.
TidyMac only removes simulators Xcode can no longer use. Others may hold test data you want.
Unusable simulators disappear from the list. Working ones stay.
When Xcode updates again.
How big it gets: 2–40 GB, mostly simulators for iOS versions your Xcode no longer supports.
Where it lives: ~/Library/Developer/CoreSimulator/Devices
Do it yourself
Open Terminal and type: xcrun simctl delete unavailable
xcrun simctl delete unavailable
See your own simulators in seconds
Scan free, see every part of your storage explained, and clean only what’s safe. Everything goes to the Trash first.
Frequently asked questions
Is it safe to delete simulators on a Mac?
TidyMac only removes simulators Xcode can no longer use. Others may hold test data you want.
Why are my simulators so big?
Each simulator keeps its own apps and data, and old ones stay behind after Xcode updates.
What happens after I remove simulators?
Unusable simulators disappear from the list. Working ones stay.
Will simulators come back?
When Xcode updates again.
How do I clean simulators manually?
Open Terminal and type: xcrun simctl delete unavailable