Open Settings
Tap Sounds & Haptics
Turn on Vibrate on Ring
Turn on Vibrate on Silent
To test vibration, switch the Ring/Silent switch on the side of the iPhone
To make the iPhone vibrate for alerts, go to Settings
Tap Notifications
Select an app
Turn on Sounds or Alerts for that app
To create a custom vibration, go to Settings
Tap Sounds & Haptics
Tap a sound type
Tap Vibration
Select a vibration pattern or create a new one
To use vibration for accessibility, go to Settings
Tap Accessibility
Tap Touch
Turn on Vibration