Apple on the new iOS 11 operating system allows users to block notification previews on the lock screen, even for individual apps
With iOS 11, Apple's new mobile operating system, we will have a variety of notifications customizations available. Some apps, for example, can be marked as "sensitive" and you can prevent their notifications from being displayed with the smartphone's screen locked.
In practice, the notification of apps that may contain confidential data, such as emails or WhatsApp, will give us previews of messages and conversations only if we open the iPhone with Face ID or Touch ID. On iOS 11 we can decide which app to lock once the screen is turned off and which to leave active. On iOS 10, on the other hand, users could only enable or block all apps that could turn on the display with their notification previews. This is a nice step forward in terms of privacy protection and cybersecurity.
How to hide previews
To prevent notification previews from appearing on the screen of our iPhone just take a few steps. First we go to the Settings section and here we click on the Notifications item. In the new tab that opens we must look for the heading Show Notifications. Once we click on the section we have to select the option "When unlocked". By default the phone is set to Always, but we will also be able to choose the Never option. That is, notifications in this case will not be shown either when the screen is off or when the screen is on.
Hiding individual apps
We mentioned, however, that on iOS 11 we can block the previews of individual apps. So how can we do to not display, for example, new WhatsApp messages? Simple, we go back to Settings and then Notifications. In the new tab we scroll to the bottom until we find a list of all applications installed on our iPhone. At this point we select the app that we want to block, in this case WhatsApp, and on the page that opens under the heading View Previews set the option "Only when phone is Unlocked". And that's it. These new personal privacy features from Apple are applicable on all iPhones updated to iOS 11, including iPhone X.