A new menu bar app shows what's eating your Mac's System Data

macOS hides gigabytes of simulator runtimes and build caches inside "System Data" — now an open-source menu bar app lets you inspect and delete them item by item.

Developer Jarvis322 released macos-sysdata, a lightweight utility for macOS 14+ built with Swift 6. The app sits in your menu bar, opens the opaque System Data bucket, and measures real disk usage for virtual machine disks, Xcode caches, and package manager stores. The project picked up 542 GitHub stars in its first week.

Why it matters: Finder dumps everything it cannot attribute to standard photos or documents into one unsearchable total. Instead of blindly wiping files, this app assigns every row a safety badge: Safe (regenerates on its own), Review (costs a re-download or login), or Manual. Items flagged for review go straight to the Trash first, giving you a 30-day safety net.

Here's the gist: install it via Homebrew by running brew install --cask Jarvis322/tap/sysdata. The app installs no background launch daemons or kernel extensions, and any action needing elevated privileges shows you the exact script before asking for approval.

Finally, a way to reclaim 50 gigabytes of old Xcode files without guessing commands in Terminal.