Jettison 1.9.7 for Mac

Mac Utilities

Updated Aug 20, 2026

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Jettison is a small menu bar utility from St. Clair Software that takes care of external disks at the moments people usually forget them. Before your Mac sleeps, it ejects connected external drives safely, and when the Mac wakes it remounts any drives still plugged in. That habit protects Time Machine backups and file server volumes from damage, and saves you from ejection warnings when you close the lid. Updated Aug 20, 2026.

Key Features

• Ejects external disks automatically before your Mac sleeps
• Remounts those disks on wake if still connected
• Eject all drives at once or one at a time
• Handles Time Machine disks and network drives
• Eject before logout, restart, shutdown or display off
• Clear errors when an app is keeping a disk busy

How to Download

1. Visit the official St. Clair Software page for Jettison.
2. Use this link to get the installer: Download from the official site and save the file to your Mac.
3. Place Jettison in Applications and launch it from the menu bar.
4. Open settings once and choose your eject and remount options.

System Requirements

Jettison needs macOS 10.13 or later and runs natively on Intel and Apple silicon Macs. It sits quietly in the menu bar, and it may ask for Full Disk Access permission so it can remount USB drives reliably after wake.

FAQs

Why eject a disk before sleep?

If a Mac sleeps mid write, files and backups can be left in a bad state, so ejecting first removes that risk.

Will Jettison remount my drives on wake?

Yes, drives it ejected are remounted on wake as long as they stay connected.

What if an app keeps a disk busy?

Jettison shows which app is holding the disk open and can offer a quit button.