MDN lists the Notifications API's `close()` method as supported in iOS Safari 16.4 but this isn't true. Calling the `close()` function doesn't do anything (doesn't throw either). I used Peter Beverloo's excellent Notification Generator and some additional local testing to confirm my findings: https://tests.peter.sh/notification-generator/ You can also use my own little (simplified) test case: https://testcase.rejh.nl/testcase-notifications-api/ MDN compat table: https://developer.mozilla.org/en-US/docs/Web/API/Notifications_API#browser_compatibility MDN `close()`: https://developer.mozilla.org/en-US/docs/Web/API/Notification/close
<rdar://problem/137605176>