iOS Simulator Caches Taking Up Space? Yes, You Can Delete Them

Yes, it's safe to deleteDiskmack safety tier: Safe to clean

~/Library/Developer/CoreSimulator/Caches

Yes, it's safe to delete the iOS Simulator caches. Everything in ~/Library/Developer/CoreSimulator/Caches is scratch data that the Simulator rebuilds the next time it runs. You won't lose simulator devices, installed apps, or any project files. The only cost is a slower first boot while the caches are recreated.

What it is

~/Library/Developer/CoreSimulator/Caches is where the iOS Simulator keeps rebuildable runtime data. The bulk of it is usually the dyld subfolder, which holds the shared caches of system libraries that the Simulator builds on your Mac for each runtime you boot. Building those caches once up front is what makes simulated apps launch quickly, so the Simulator writes them out and reuses them on every boot after that.

The folder grows with the number of runtimes you touch. Each iOS, watchOS, tvOS, or visionOS runtime gets its own cache, often several gigabytes apiece. The caches are also keyed to the macOS build that created them, so after a macOS update the Simulator writes a fresh set and the old one just sits there. Test across a few iOS versions and let a couple of macOS updates go by, and the folder can quietly reach 10 to 20 GB or more. Nothing you created lives here: no source code, no app data from your simulators, no settings.

Is it safe to delete?

This is one of the safest large deletes on a developer Mac. The caches are derived entirely from the runtime images, so the Simulator can rebuild every byte. Delete the folder's contents and the next simulator boot regenerates what it needs for the runtime you launch. That first boot will be noticeably slower, sometimes by a few minutes, and then everything is back to normal.

The one thing to get right is scope. Delete the contents of Caches, not the whole CoreSimulator folder. Its sibling Devices folder holds your actual simulator devices, including any apps and data you've installed on them, and that is a different decision. Diskmack identifies the Caches folder automatically and cleans it the safe way, leaving Devices untouched.

How to check its size

In Finder: In Finder, choose Go > Go to Folder (or press Command-Shift-G), paste ~/Library/Developer/CoreSimulator, and press Return. Select the Caches folder and press Command-I to see its total size.

In Terminal:

du -sh ~/Library/Developer/CoreSimulator/Caches

The ~ expands to your home folder automatically, and the path has no spaces, so no quotes are needed.

How to clean it

Quit the Simulator app and Xcode so nothing is writing to the folder.
In Finder, choose Go > Go to Folder (Command-Shift-G) and paste ~/Library/Developer/CoreSimulator/Caches.
Press Command-A to select everything inside, then move it to the Trash (Command-Delete).
Empty the Trash to reclaim the space.
Boot a simulator once and let it rebuild its cache. That first launch takes longer than usual; later launches return to normal speed.

Stay inside Caches. The neighboring Devices folder contains your simulator devices and their installed apps, and deleting it wipes them.

Will it come back?

Yes, and quickly. The caches are recreated when simulators run, so the folder starts refilling the first time you boot one after cleaning. It only rebuilds caches for runtimes you actually use, though. If the old size came from runtimes you no longer test against, most of that space stays free. For a lasting reduction, also remove unused simulator runtimes in Xcode's Settings, under Platforms (called Components in older versions).

Common questions

Will deleting the Simulator caches break Xcode?

No. Xcode and the Simulator treat this folder as disposable. The next simulator boot rebuilds the cache for whatever runtime you launch. The only symptom is that first boot being slower.

What is the dyld folder inside Caches, and why is it so large?

It holds the shared caches of each simulator runtime's system libraries, one set per runtime per macOS build. These are the main reason the folder reaches multiple gigabytes, and they're safe to delete along with everything else in Caches.

Is this the same as ~/Library/Developer/CoreSimulator/Devices?

No, and the difference matters. Devices holds your simulator devices themselves, including apps and data installed on them. Caches holds rebuildable scratch data. Clean Caches freely; treat Devices as a separate, more careful cleanup.

Can I delete the whole CoreSimulator folder instead?

You can, but you would also erase every simulator device and any test data on them. Xcode recreates default devices later, but anything you installed on them is gone. If your goal is disk space with no side effects, stick to the Caches folder.