4 Hide Notification Previews
Available in different forms over the past few years, iOS 11 now offers the ability to set notification privacy both globally (for all your apps), or on an app-by-app basis. This features allows Apps to display a notification alert on your lock screen, without revealing the actual content of the notification.
By doing this, someone looking at your locked iPhone may know that you have an alert from Twitter, iMessage, Facebook, or even your bank, but the actual contents are hidden until you enter your passcode or unlock the device with TouchID.
- Show Previews.
- Select Never (or When Unlocked).