Is it safe to delete CoreSimulator Devices on Mac?

Part of our guide to how much space Xcode takes · Tested with Xcode 26.5 · Updated September 2026

Short answer: yes for simulators you don't need, but do it with xcrun simctl, not by deleting folders. ~/Library/Developer/CoreSimulator/Devices holds one folder per simulator (its apps, data and settings). Deleting folders by hand while Xcode or Simulator runs can leave broken entries; simctl keeps Xcode's device list consistent.

What's inside

Each simulator you've created (or Xcode created for you with each runtime) has a folder named by its UUID. On our test Mac there were 35 device folders using 577 MB, 22 of them "unavailable" because their runtime was gone. Simulators you actively test with grow with every app build and its data.

What	Where	Safe to delete?
Unavailable simulators	Runtime no longer installed	Yes: `xcrun simctl delete unavailable`
Simulators you don't use	Old device types, duplicates	Yes: `xcrun simctl delete <UUID>`
Data inside a simulator	Apps and content you installed	Yes: `xcrun simctl erase <UUID>` (or `erase all`)
Simulators you test on	Current runtime	Keep, or erase their contents
Runtimes (the OS images)	Separate; listed by `xcrun simctl runtime list`	See delete old simulator runtimes

See what's there

xcrun simctl list devices
du -sh ~/Library/Developer/CoreSimulator/Devices

Clean it safely

# Quit Simulator first
xcrun simctl shutdown all
xcrun simctl delete unavailable
# Optional: reset every simulator's content (keeps the devices)
xcrun simctl erase all

Xcode recreates a default set of simulators for each installed runtime, so you won't end up with none.

Don't delete the whole CoreSimulator folder. It also contains runtime and cache data Xcode expects; deleting it can make Xcode report "no simulators available" until you reinstall runtimes.

All of Xcode in one list. Storage Cleaner finds unavailable simulators, old runtimes, device support and DerivedData, removes simulators through simctl so Xcode stays consistent, and shows when you last used each item.

Try Storage Cleaner free

Frequently asked

What does "unavailable" mean? The simulator's runtime (its iOS version) is no longer installed, so it can't boot. Deleting it frees space and changes nothing you can use.

Will deleting simulators delete my app's code? No. Only the copy installed in that simulator and its data.

Why is CoreSimulator still big after deleting devices? Runtimes are the large part (about 8.5 GB each). See delete old runtimes.