The short answer
Yes. On both iPhone and Android, alarms set in the system clock are designed to sound through silent mode and Do Not Disturb. Alarms that stay silent are usually caused by ringer volume at zero, Bluetooth audio routing, or a custom Focus mode rather than by silent mode itself.
iPhone
The silent switch and Do Not Disturb do not silence Clock app alarms. If yours is silent, the cause is elsewhere.
- Ringer volume is separate from media volume, and the side buttons usually adjust media. Check Settings → Sounds & Haptics.
- A connected Bluetooth device can capture the audio. Disconnect and retest.
- A custom Focus mode — not standard Do Not Disturb — can behave differently. Test with all Focus modes off.
Android
Android splits volume into separate streams, and the alarm stream is its own. Turning the ringer to silent does not touch it.
- 1Press a volume key, tap the settings or three-dot icon, and check the Alarm slider specifically.
- 2Open Settings → Sound → Do Not Disturb → Exceptions and confirm that Alarms are allowed.
- 3Check that a third-party alarm app is using the alarm audio stream rather than the notification stream. Apps that post a notification instead of a real alarm inherit notification rules.
The reliable test
Set an alarm for two minutes from now, switch on silent and Do Not Disturb, lock the phone and put it face down. If it rings, silent mode is not your problem. This takes two minutes and settles the question permanently.
Roosta uses the system alarm path on both platforms, which is what makes it audible through silent mode and Do Not Disturb, and why it does not depend on notification permissions to wake you.