Is it safe to delete DerivedData?

Yes. Xcode rebuilds it the next time you build, so the only cost is a slower first build. Close Xcode first.

Can I delete old iOS DeviceSupport folders?

Usually. Xcode re-creates the folder for a device and iOS version the next time you connect that device, which takes a few minutes.

Why are simulators always Check First in Peekaboo?

Deleting a simulator also deletes the apps and data inside it, so it isn’t something to clear without looking.

Do I need the developer features turned on?

Yes. Show developer features in Settings adds Projects, Dotfiles & Config, and Xcode and package-manager cleanup to Peekaboo. They stay hidden until you turn them on.

Peekaboo · Xcode and developer cleanup

Get back the space Xcode and your dev tools quietly took

Xcode alone can hold tens of gigabytes in build files, device support, archives and simulators, and npm, CocoaPods and Homebrew add their own caches. Peekaboo lists each folder, says what it is and what happens if it goes, and lets you remove it with an undo.

Download free trial14 days free · macOS 14+ · Added in 0.1.0 · Updated November 7, 2026

What it does

Every developer folder, explained: Xcode build files, caches, device support and archives, simulators, and package-manager caches, each explained before anything moves.
Safe items first: Rows marked Safe can be cleared in one step with Clean Safe Items, and Cleanup History puts them back. Simulators are always Check First.
Trash by default: Files go to the Trash. Things that can’t, such as simulators and runtimes, Homebrew packages and local Time Machine snapshots, are removed only if you turn on permanent removal in Settings ▸ Cleanup.
Your projects, as cards: Projects shows your git repositories with branch, last commit and the rebuildable folders inside them, such as build output and dependencies, ready to move to the Trash.

How to use it

1Turn on Show developer features in Settings.
2Open Clean Up and choose the developer cleanup: Xcode data, simulators and package caches.
3Read what each row is, then clear the Safe ones or pick by hand.

When another app fits better

Peekaboo doesn’t manage Xcode versions or simulator runtimes the way Xcode’s own Settings ▸ Platforms or xcrun simctl do, and it won’t clean inside Docker. For removing old Xcode versions themselves, its App Uninstaller handles the app.

Questions

Is it safe to delete DerivedData?: Yes. Xcode rebuilds it the next time you build, so the only cost is a slower first build. Close Xcode first.
Can I delete old iOS DeviceSupport folders?: Usually. Xcode re-creates the folder for a device and iOS version the next time you connect that device, which takes a few minutes.
Why are simulators always Check First in Peekaboo?: Deleting a simulator also deletes the apps and data inside it, so it isn’t something to clear without looking.
Do I need the developer features turned on?: Yes. Show developer features in Settings adds Projects, Dotfiles & Config, and Xcode and package-manager cleanup to Peekaboo. They stay hidden until you turn them on.