The keys are still on the right side of the S21 series, but if you just got your phone and want to know which key combination can turn off or restart the S21, here is the way.
Turn off or restart the Galaxy S21
- Press the volume down and power keys at once.
- Hold them until the switch-off/restart/emergency mode virtual buttons menu appears.
- Tap on the big red Power off icon at the top, or the green Restart button in the middle.
- Go to Advanced features > Side key > How to power off your phone for more options.
- Alternatively, you can go to Advanced features > Side key > How to power off your phone, and set the long-press of the side key to show up the restart menu, instead of calling up Bixby.