MonoSlice

Most Mac apps ship as Universal binaries with both Apple Silicon (arm64) and Intel (x86_64) code, yet a Mac only ever runs one of them. MonoSlice detects the host architecture, scans /Applications or any folder for apps that carry the slice you do not need, removes it and re-signs each app so it still launches. Large apps can shrink by hundreds of megabytes.

• A Mac app in SwiftUI: scan, see the potential savings per app, and slim apps one by one or in a batch; it runs from the Dock or the menu bar.
• A command-line tool, monoslice, for scripts and one-off use.
• Originals can go to the Trash instead of being deleted, so an optimized app can be put back; apps can be excluded for good.
• History marks apps that an update made Universal again and shows how much space has been saved.
• Six languages: English, Russian, German, Spanish, Polish and Czech.

How it is built

• Built on the system lipo and codesign tools; optimized apps keep the Hardened Runtime and the entitlements an ad-hoc signature can carry.
• Administrator rights only for the final swap of an app in a protected location, after the optimized copy has been verified.
• No network access and no data collection: it works fully offline.
• Distributed outside the Mac App Store as a Developer ID app, signed and notarized by Apple, because the App Store sandbox does not allow modifying other apps.