DerivedData, iOS Simulators, Device Support files, npm, Gradle, pip, CocoaPods, and Homebrew caches — a developer Mac can accumulate 30–80 GB of build artifacts that are safe to delete. CleanMachine finds them all in one scan. Free to see, $19.99 to clean.
macOS 13+ · Apple Silicon & Intel · Scanning always free
Every time you build an Xcode project, the compiled artifacts go to ~/Library/Developer/Xcode/DerivedData/. Xcode keeps builds for every project you've ever worked on — even projects from years ago. On an active iOS/macOS developer machine, DerivedData can easily reach 10–30 GB. Clearing it is completely safe: Xcode will rebuild on next compile (taking a few extra minutes).
Each iOS Simulator in ~/Library/Developer/CoreSimulator/Devices/ is a complete virtual iPhone or iPad with its own filesystem. Every iOS version and device combination Xcode ever downloaded or ran creates a directory here. After a few years you might have 20+ simulators you no longer use. Each is 500 MB–2 GB.
Every time you connect a new iOS device or upgrade iOS, Xcode copies support files (~2–5 GB per version) to ~/Library/Developer/Xcode/iOS DeviceSupport/. Files for old iOS versions you no longer develop for are safe to remove.
Node.js stores a local package cache in ~/.npm/_cacache/. Every package you've ever installed via npm is cached here — even versions from projects you've deleted. The npm team actually recommends clearing this periodically with npm cache clean. CleanMachine does this without the Terminal.
Android/Java developers: Gradle stores build caches in ~/.gradle/caches/. This can reach 5–10 GB on an active Android project and is completely safe to clear — Gradle will re-download what it needs on the next build.
Python's pip stores downloaded wheels in ~/Library/Caches/pip/. Safe to clear — pip re-downloads packages when needed.
CocoaPods stores a local spec cache in ~/Library/Caches/CocoaPods/. On iOS developer Macs this can be 1–3 GB and is safe to delete.
Homebrew keeps downloaded package archives in ~/Library/Caches/Homebrew/. After brew upgrade installs new versions, the old archives stay. Usually 500 MB–3 GB of safely removable data.
Download CleanMachine and run Developer Junk scan — completely free. See real-time sizes for each category. Only $19.99 once to clean them all up — with category-by-category control.
macOS 13+ · Apple Silicon native · No subscription · 30-day money-back guarantee
No. DerivedData contains only build artifacts — compiled binaries, indexes, and build logs. Your source code is in your project directory. After clearing, Xcode will do a full rebuild on the next build (which takes longer than an incremental build, but is otherwise identical). Your breakpoints, schemes, and settings are unaffected.
Yes. Simulators can be re-added through Xcode → Preferences → Components at any time. They download and install in a few minutes. CleanMachine puts deleted simulators in CleanMachine Trash first, so you can also restore them from there if you change your mind immediately.
Never. CleanMachine's Developer Junk scanner only looks at the eight specific cache/build artifact directories listed above. Your project files, git repositories, virtual environments, and installed Node modules (node_modules) are not touched.