How to delete Xcode simulator runtimes and get gigabytes back
A simulator runtime is the iOS, watchOS, tvOS or visionOS system that your simulators run. Each one is a disk image of several gigabytes, and Xcode keeps every runtime you ever installed. On a Mac that has been through a few Xcode releases, old runtimes are some of the biggest files you can safely remove.
Runtimes, devices and data are three different things
People mix these up, and it changes what is safe to delete:
| Thing | What it is | Where |
|---|---|---|
| Runtime | The OS image (iOS 26, watchOS 26 and so on) | Disk images managed by macOS, listed with simctl |
| Simulator device | One virtual iPhone or iPad that uses a runtime | ~/Library/Developer/CoreSimulator/Devices |
| Device data | The apps and files inside a simulator | Inside each device folder |
This guide is about the first row. For the other two, read how to reset or delete iOS simulators from Terminal.
List your runtimes
xcrun simctl runtime listYou get one line per runtime, with its identifier and state, and a total at the end:
== Disk Images ==
-- iOS --
iOS 26.5 (23F77) - 5D029027-5086-461A-9722-7B1DB03855DC (Ready)
iOS 27.0 (24A434) - 63C01034-F52D-4E69-BD84-E9A8D06BCD90 (Ready)
-- watchOS --
watchOS 26.5 (23T570) - B9CD6C08-FDDD-4539-AB54-5B2AA3241430 (Ready)
watchOS 27.0 (24R362) - 7CA54B5F-8BE7-49E2-96F3-2D60135BBF61 (Ready)
Total Disk Images: 4 (22.6G)That is a real list. Four runtimes added up to 22.6 GB, and removing the two old ones took it down to 11.1 GB.
Delete a runtime from Terminal
Copy the identifier of the runtime you no longer need and delete it:
xcrun simctl runtime delete 5D029027-5086-461A-9722-7B1DB03855DCThe state changes to Deleting for a short while, then the runtime disappears from the list. simctl can also choose for you:
# See what would be removed, without removing anything
xcrun simctl runtime delete --notUsedSinceDays 90 --dry-run
# Remove runtimes that have not been used for 90 days
xcrun simctl runtime delete --notUsedSinceDays 90
# Remove runtimes your Xcode can no longer use
xcrun simctl runtime delete --unusable
# Remove runtimes that are older than the one your Xcode needs
xcrun simctl runtime delete --outdatedUse --dry-run first. It prints what would go and does nothing else.
Delete a runtime in Xcode
Open Xcode → Settings and look for the Components tab (older Xcode versions call it Platforms). Each installed runtime has a size next to it. Select one and choose the minus button to remove it. The same tab is where you download a runtime again.
What it costs you
- You can no longer run apps on that OS version in the simulator until you reinstall it.
- Reinstalling means a download of several gigabytes.
- Your projects, simulators and source code are not affected.
A sensible habit: keep the runtime for your minimum supported OS and the newest one, and delete the versions in between that you never test on.
Other Xcode folders worth checking
Runtimes are only part of Xcode’s footprint. DerivedData, iOS DeviceSupport and Archives each have their own rules. The full checklist is in how to free up disk space on a Mac as a developer.
Quick answers
Does deleting a simulator runtime delete my simulators?
No. The runtime is the operating system image. Simulator devices that use a runtime you deleted stay in the list but show as unavailable until you install that runtime again.
Can I get a runtime back after deleting it?
Yes. Open Xcode, go to Settings, choose Components (called Platforms in older versions) and download the runtime again.
Is it safe to delete the newest runtime?
It is safe, but the simulator can only run apps on runtimes you have installed. Keep the runtime for the OS versions you test on.