What's in ~/Library/Developer, and what's safe to delete

Part of our guide to why System Data is so large on Mac · Updated September 2026 · 5 min read

~/Library/Developer is where Xcode and Apple's developer tools keep their working data. On a Mac used for iOS or macOS development it's commonly 20–100 GB, and macOS counts all of it as System Data. Here's what each folder is and whether you can delete it.

See the sizes

du -sh ~/Library/Developer/* ~/Library/Developer/Xcode/* 2>/dev/null | sort -hr | head -20

Folder by folder

Folder	What it is	Safe to delete?
`Xcode/DerivedData`	Build output and indexes for every project	Yes, rebuilt on next build
`Xcode/iOS DeviceSupport` (and watchOS, tvOS, visionOS)	Debug symbols per device OS version	Yes for versions you no longer test
`Xcode/Archives`	Archived builds with their dSYMs	Careful: keep versions still in use
`Xcode/UserData/Previews`	SwiftUI preview simulators and builds	Yes, recreated when previews run
`Xcode/UserData` (the rest)	Your Xcode settings, key bindings, code snippets, themes	No
`CoreSimulator/Devices`	Your simulators, with their installed apps and data	Use `xcrun simctl delete unavailable`, not Finder
`CoreSimulator/Caches`	Simulator caches	Yes, with the Simulator app closed
`Xcode/Products`	Build products for some schemes	Yes
`Xcode/DocumentationCache`, `Xcode/*.log`	Downloaded docs and logs	Yes

Simulator runtimes aren't in this folder: current Xcode stores them as disk images elsewhere. Remove them with xcrun simctl runtime delete (guide).

The biggest wins, in order

Old simulator runtimes: about 8.5 GB each (how).
DerivedData for projects you no longer build (how).
DeviceSupport for old iOS versions (how).
Unavailable simulators: xcrun simctl delete unavailable.

Quit Xcode and the Simulator before deleting anything here, and prefer moving folders to the Trash so you can restore them. Never delete Xcode/UserData as a whole: it holds your settings.

How much Xcode takes on a fresh install is in our Mac developer storage statistics 2026: 13.6 GB before you build anything.

Rather see it all at once? Storage Cleaner finds everything in ~/Library/Developer, labelled Safe, Review or Caution, in one scan, shows when you last used each item and whether it's safe to remove, and cleans to the Trash with Undo. Scanning is free.

Try Storage Cleaner free

Frequently asked

Can I delete the whole ~/Library/Developer folder? Xcode would recreate what it needs, but you'd lose your simulators' data, your archives and your Xcode settings. Delete the specific folders above instead.

Is it the same as /Library/Developer? No. /Library/Developer (without the ~) holds system-wide components such as command line tools and simulator runtime images. Leave it to Xcode and simctl.