How to stop random alert notifications on iMac running macOS 26.1?

Go to Safari > Settings > Websites > Notifications, and remove all websites you have previously allowed to send you Notifications.

Yes, great idea! That sparked a few options I just remembered. First, the alert will be coming from the automations tab, but it is still good to check the main view.

Second, What are you doing every 20 seconds (pun not intended)?

Third, check ~/Library/launchAgents (hold on the ⌥ key and click on the Go menu in the finder menu bar, then click Library.) Also check Macintosh HD/Library/launchAgents. These folders hold system and user level automations.

Note: the launch agents will be in the form of .plist files, open them using ⌘+Y and look to see if they are what you are looking for. There are probably a lot. Just know that you must be sure that it is ok to delete, here is what you do, you go to terminal, enter

launchctl unload ~/Library/LaunchAgents/com.example.agent.plist

replace com.example.agent.plist with the actual name of the plist, and change the file link as needed. Then if it worked you can delete the file.

Bruce Plummer wrote:

I'm not receiving a visual image of the notification; just an audible as I previously disabled all application notifications in Settings>Notifications. The sound is a sort of like a bell or chime and it repeats every 20-30 seconds.

OK that is good info.

Audible alerts can come from a long list of different App's and UI sources.

New Mail, Messages, Reminders, etc... to bad Keystrokes and Mouse clicks

To stop audible alerts, go to System Settings > Sound > turn off "Play user interface sound effects"

What notification(s) are you getting..?

Please include a (Shift+Command+4) screenshot of the notification(s).

see > Take a screenshot on Mac - Apple Support

Then post the screenshot using the Image Insertion tool on the forum toolbar.

Ok, one more thing to check. See if you have a Shortcut in the Shortcuts app that is playing a sound at a regular interval. I have found many Shortcuts that can be downloaded, usually on Social Media sites, that make a voice announcement at regular intervals. This can also be done to play a sound and set to run on startup.

Also, see if the problem persists when starting in Safe Mode:

Start up your Mac in safe mode - Apple Support

The Automations tab in the shortcuts app.

If you’ve played around in settings then you might have changed the screenshot quick key (⇧+⌘+4) to something else. If that is the case then open the launchpad and search for screenshot. Open the app and snap a picture of the alert.

Note: for your privacy only snap the alert, make sure that no sensitive content is displayed.

Gandolf243 wrote:

If you’ve played around in settings then you might have changed the screenshot quick key (⇧+⌘+4) to something else. If that is the case then open the launchpad and search for screenshot. Open the app and snap a picture of the alert.

Note: for your privacy only snap the alert, make sure that no sensitive content is displayed.

Did you mistakenly post this reply to me instead of Bruce Plummer...?

Do you have an timer on? That will be in the alarm app, and there is no way to stop the alarm app from sending notifications. It uses a restricted framework only know by apple.