>

Quit or Restart a Frozen App with killall

Force-quit a hung macOS application by name from the terminal using killall, then relaunch it in one more command.

macOSProcessesTerminalkillallMedium risk
Run killall Safari to force-quit the frozen app by name, then open -a Safari to relaunch it.

01Command

Command
$ killall Safari

02What it does

killall sends a process a termination signal matched by its exact name, which is often faster than hunting for Force Quit when an app is beachballing — and it works even when the app's menus no longer respond. Follow the quit with open -a to restart the app fresh, which usually clears the hang. Use killall with no arguments or check Activity Monitor if you are not sure of the process name; killing a system daemon instead of an app requires sudo and more care.

03Risk

RiskMedium risk
RequirementsNeeds sudo only for processes owned by other users or the system; find the exact process name with ps ax | grep AppName.
!Warning: killall terminates without saving: unsaved documents in the killed app may lose changes unless the app autosaves. Only use sudo killall on daemons (like killall -HUP mDNSResponder) when following trusted instructions, since system processes do not always restart on their own.

04Undo

Undo
$ open -a Safari

05Sources

  • killall - kill processes by name
    SS64 · technical · 2026-09-17
    Evidence: Documents killall for terminating processes by name, including sudo usage for other users' processes.
  • Quit an app on Mac
    Apple · vendor-doc · 2026-09-17
    Evidence: Apple's guidance on quitting unresponsive apps, confirming the everyday need killall addresses from the command line.

Last verified: 2026-09-18 · Category: System & Settings

06Related solutions

Change where screenshots are saved on Mac
macOSScreenshotTerminaldefaults

Point macOS screen captures at any folder you choose instead of the desktop.

Medium risk ✓ 2026-09-16
Download a file from a URL on Mac with curl
macOSTerminal

Grab any file from the web straight into the current folder — no browser needed.

Low risk ✓ 2026-09-16
Find files larger than 500 MB on Mac
macOSFilesTerminal

List the biggest files in your home folder that are eating disk space.

Low risk ✓ 2026-09-16