You can change the sound used by a regular iPhone alarm from the Clock app. The alarm’s volume is controlled separately from media volume, and Sleep/Wake Up alarms can have their own settings.
Change a Regular Alarm Sound
- Open the Clock app.
- Select Alarms.
- Tap the alarm you want to change, or tap Edit and select it.
- Tap Sound.
- Choose a ringtone, vibration, or other available alarm sound.
- Tap Back and Save if your iOS version presents those controls.
Adjust Alarm Volume
Open Settings > Sounds & Haptics and adjust the volume associated with ringtones and alerts. You can also review the setting that allows the side buttons to change that volume. Test the alarm after making changes.
Silent Mode Does Not Work Like Media Playback
Do not assume that putting the iPhone in silent mode is equivalent to turning off alarm sounds. Alarms are designed to alert you even when other notification behavior is muted. If you need a specific result, test the actual alarm configuration.
Sleep or Wake Up Alarms
Sleep schedule or Wake Up alarms can have additional controls tied to the Health or Clock sleep-schedule experience. If the sound you want to change is part of a sleep schedule rather than an ordinary Clock alarm, open that schedule and review its alarm options.
Test Before Relying on It
After changing the sound or volume, set a temporary alarm a few minutes ahead and confirm that the sound and volume are what you expect. This is especially useful before relying on an alarm for an important appointment.
Summary
Use Clock > Alarms to change a regular alarm’s sound, and use Sounds & Haptics for alert volume. Sleep/Wake Up alarms can have separate controls, so test the exact alarm you rely on.