To turn off Galaxy S21 Ultra, press and hold the Side and Volume down buttons together until the Power menu appears, then tap Power off twice to confirm. This is the primary Samsung-documented method for powering your phone on and off when the Side key is set to open Bixby by default.
How to turn off Galaxy S21 Ultra with the button shortcut
The Side button is located on the right side of the device, below the volume rocker. Samsung documents this as the standard shutdown method for the Galaxy S21 Ultra. Press and hold the Side and Volume down buttons simultaneously for a few seconds. When the Power menu appears, tap Power off, then tap Power off again to confirm. The device will shut down within a few seconds.
How to turn off Galaxy S21 Ultra from Quick settings
- Swipe down from the top of the screen using two fingers to open the Quick settings panel.
- Tap the Power icon in the upper-right corner, next to the Settings icon.
- Tap Power off, then tap Power off again to confirm.
Samsung presents this as a Galaxy phone method with no model-specific exception for the S21 Ultra.
How to turn off Galaxy S21 Ultra with Bixby voice
- Set up Bixby Voice first through the device setup process.
- Press and hold the Side button to call Bixby. The Bixby button is located below the volume rocker on the left side of the device.
- Say "Turn off the phone" or "Turn off the tablet."
Bixby will initiate the power-off process.
How to remap the Side button to open the power menu
- Open Settings.
- Tap Advanced features.
- Tap Side button.
- Under Long press, select Power off menu.
After remapping, pressing and holding the Side button opens the Power off menu instead of Bixby. The Power off menu then includes options for powering off or restarting, plus emergency calls and medical info.
Frequently Asked Questions
Does the Side button alone turn off the Galaxy S21 Ultra?
Not by default. The long press can be set to open Bixby or the Power off menu, depending on the setting at Settings > Advanced features > Side button > Long press.
What is the exact shutdown shortcut on the S21 Ultra?
Press and hold Side + Volume down together, then tap Power off, then tap Power off again to confirm.
Can the phone be turned off from Quick settings?
Yes. Swipe down with two fingers to open the Quick settings panel, tap the Power icon, then tap Power off and confirm.
Can Bixby shut it down?
Yes, after Bixby Voice is set up. Press and hold the Side button to call Bixby, then say "Turn off the phone."
Will turning off my Galaxy S21 Ultra delete any data?
No. Turning off the device powers it down without affecting stored data or settings.
How do I force restart the Galaxy S21 Ultra if it's unresponsive?
If the Galaxy S21 Ultra doesn't respond to the standard power-off method, perform a forced restart by pressing and holding the Side key and the Volume down button for about 10 seconds until the device restarts.
