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How to Lock Diary AI on iPhone

iOS 18 Face ID lock and Hidden folder · Lachlan Sonter · checked November 2026

Time needed
4 taps
Needs iOS 18 or later

Works for Diary AI whether or not it has its own passcode. No download needed.

Short answer

Touch and hold Diary AI's icon, tap Require Face ID, then confirm. On iOS 18 and later that puts Diary AI behind Face ID, Touch ID or your passcode; choose Hide and Require Face ID instead to move it into App Library's Hidden folder as well.

Lock Diary AI with Face ID

  1. Find Diary AI on your Home Screen or in App Library.
  2. Touch and hold the icon until the quick-actions menu opens.
  3. Tap Require Face ID (or Require Touch ID / Require Passcode, depending on your iPhone).
  4. Tap Require Face ID again to confirm. Diary AI now asks for authentication every time it opens.

To test it, close Diary AI from the App Switcher and open it again. You should see the Face ID prompt before any content appears.

Hide Diary AI in App Library

  1. Touch and hold Diary AI's icon and tap Require Face ID.
  2. Choose Hide and Require Face ID instead of Require Face ID.
  3. Confirm. The icon leaves your Home Screen and moves to the Hidden folder at the bottom of App Library.
  4. To open it later, swipe to App Library, tap Hidden and authenticate.

Hiding also locks the app. To undo either, touch and hold the icon again and choose Don't Require Face ID.

Why lock Diary AI?

Diary AI's privacy label lists sensitive info and user content — the kind of data you would not want on screen if someone borrows your unlocked phone. Journals collect your private thoughts, moods and often your location and photos. A lock screen inside the app is not the same as encryption of the synced entries.

Health and fitness apps can read Apple Health data only for categories you approve, one by one. What they collect themselves is shown on the label.

A lock answers one question — who can open the app on this iPhone. It does not change what Diary AI sends to its developer; for that, see Diary AI's full privacy report.

What the lock does and does not do

It does

  • Ask for Face ID, Touch ID or passcode every time Diary AI opens
  • Hide message previews in notifications
  • Keep Diary AI's content out of Spotlight and Siri suggestions
  • With Hide, remove the icon from the Home Screen

It does not

  • Stop someone who knows your passcode
  • Encrypt or change how Diary AI stores data
  • Sync to your iPad or other devices
  • Remove Diary AI from purchase history or Screen Time reports

Don't see Require Face ID?

  • Update to iOS 18 or later in Settings › General › Software Update.
  • Make sure a passcode is set in Settings › Face ID & Passcode; the lock needs one.
  • Some Apple apps (Settings, Calculator, Camera, Maps, Find My, Clock) cannot be locked or hidden.
  • If your iPhone is managed by work or school, the option may be restricted.

Other settings worth checking for Diary AI

  1. Tracking

    Settings › Privacy & Security › Tracking. If “Allow Apps to Request to Track” is off, apps cannot ask, and they are told to treat you as having declined. You can also turn it off for this app alone.

  2. Photos

    Settings › Privacy & Security › Photos. Limited Access lets you pick exactly which pictures the app can see; Add Photos Only lets it save without reading your library.

  3. Health

    Health app › your profile picture › Apps › Diary AI. Turn categories on one at a time; the app cannot tell which ones you declined.

  4. Sign-in

    When creating an account, Sign in with Apple can give the app a relay address from Hide My Email instead of your real one.

  5. Notifications

    Settings › Notifications › Diary AI › Show Previews: When Unlocked keeps message and account details off the Lock Screen.

Diary AI's full privacy label

App Privacy label Developer-reported · checked November 1, 2026
Used to track you
0types

None declared

Linked to you
7types
Not linked to you
0types

None declared

Is Diary AI safe? Every data type explained →

Lock these apps too

After you lock Diary AI

Tick what you have done
Tick each step as you do it on your iPhone.

Done. You have applied every control the label points to.

FAQ

Does Diary AI have its own passcode?
Some apps offer an in-app PIN or biometric lock in their settings. The App Store privacy label does not say whether Diary AI does; the iOS 18 lock works regardless.
What happens to Diary AI's notifications when it is locked?
Locked and hidden apps do not show message previews or content in notifications, and their content does not appear in Spotlight search or Siri suggestions.
Can someone who knows my passcode open a locked app?
Yes. If Face ID fails, the lock falls back to your device passcode. Keep the passcode private if the lock matters to you.
Is a locked Diary AI encrypted?
The lock controls who can open the app on this iPhone. It does not change how the app stores or syncs data. Encryption depends on the developer and on your device passcode.
Why can't I see the Require Face ID option?
You need iOS 18 or later. Some Apple apps such as Settings, Calculator, Maps and Camera cannot be locked or hidden.
Does hiding Diary AI remove it from my purchase history?
No. Hidden apps still appear in App Store purchases and in Settings › Apps, and Screen Time reports still include them.

Is Diary AI safe? Full privacy report →Does Diary AI track you? →Lock an app: A–Z →All health & fitness apps →

Facts on this page come from Apple: lock or hide an app on iPhone, as reported by the developer. Checked November 2026. How we collect data · Report a correction