Locking apps with Face ID: what it hides

Locking an app puts Face ID, Touch ID or your passcode in front of it. Hiding an app also takes it off your Home Screen. Both arrived in iOS 18, and both are useful for keeping a borrowed phone from turning into a tour of your messages. Neither stops someone who knows your passcode, except in the one case Stolen Device Protection covers, and neither hides the fact that the app is installed.

What locking an app does

Apple’s iPhone User Guide says that locking an app “requires Face ID, Touch ID, or your passcode to open it.” Apple lists what else changes:

• Information inside a locked app won’t appear in CarPlay, notification previews, search, Siri suggestions or your call history.
• Opening the app doesn’t unlock it for good. It locks again automatically after you quit it.
• The lock applies to that iPhone only. Apple says the locked or hidden status doesn’t sync with iCloud, so lock the app separately on your iPad.

Apple’s own wording varies a little. Its Personal Safety guide says locked app information won’t appear in “some locations” on your iPhone, and the iOS 18 announcement says content is hidden “from search, notifications, and other places across the system.” Take it as a strong reduction, not a promise that the app leaves no trace anywhere.

Apple’s iPhone User Guide, linked below, has the current steps for locking and hiding an app.

Apps you can’t lock

Apple says some built-⁠in apps can’t be locked. Its examples include Calculator, Camera, Clock, Contacts, Find My, Maps, Shortcuts and Settings. Photos is not on that list, but Apple doesn’t confirm in writing that it can be locked. Check on your own phone.

What hiding an app adds

Hiding goes one step further. Apple says hiding an app “removes it from the Home Screen, App Library, and search results,” and moves it to a Hidden folder in App Library that needs authentication to open.

Only apps you downloaded from the App Store can be hidden. Apple says apps that come installed on the iPhone can’t be.

Where hidden apps still show up

Hiding an app hides the icon, not the fact that you have it. Apple’s Personal Safety guide lists places where the names of hidden apps can still appear:

• Settings > Apps > Hidden Apps (this needs Face ID, Touch ID or your passcode)
• Settings > Screen Time
• Settings > Battery > Battery Health & Charging
• Your App Store purchase history

Families add another layer. Apple says children under 13 in a Family Sharing group can’t lock or hide apps at all. Teens aged 13 to 17 can, but a parent or guardian in the group can still see that the app was downloaded, see how much it is used, and restrict it with Screen Time.

If your worry is someone who would go looking for a specific app, assume they can find its name.

Your passcode opens locked apps

The weak point is the same as the Hidden album in Photos: the passcode. Apple’s rule is Face ID, Touch ID or passcode. Anyone who knows your passcode can open any locked app.

There is one exception. With Stolen Device Protection on, Apple says locking an app extends that protection to the app, so away from familiar locations it “can be opened only with Face ID or Touch ID.” At familiar places such as home, the passcode works as usual, unless you set Stolen Device Protection to Always.

So if a partner, child or roommate knows your passcode, locked apps are not private from them, especially at home.

Locking is a door, not a safe

Apple describes locking as a check before the app opens. Its pages don’t say that locking changes how the app stores or encrypts its data. What protects the data inside is whatever the app itself does. If an app syncs your photos to a cloud service, that copy is protected by the service’s settings, not by the lock on your phone.

That is fine for many uses. It is worth knowing before you rely on a lock for something sensitive.

When locking is enough, and when it isn’t

Locking or hiding is usually enough when:

• you hand your phone to a friend to make a call or look at one photo
• children use your phone for games and you want your messages out of reach
• you want message previews off your lock screen and out of search

It isn’t enough when:

• someone who might look also knows your passcode
• you don’t want anyone to know the app is installed at all
• the photos inside need protection that doesn’t depend on your phone’s passcode

For the last case, use a separate app with its own PIN or pattern that encrypts the photos with its own key. If you also hide that app, its name still appears in the places listed above: it protects the photos, not the fact that the app exists.

A quick setup checklist

1. Update to iOS 18 or later.
2. Turn on Stolen Device Protection, so locked apps need Face ID or Touch ID away from familiar places. Consider Always if the risk is at home.
3. Lock the apps that hold private messages and photos.
4. Hide App Store apps you don’t want on your Home Screen, knowing their names still show in the places above.
5. If someone may have seen your passcode, change it.