How to protect files on iPhone.

Start with a strong iPhone passcode, then choose a control that matches the files you have. A built-in Apple option may already be enough.

Secure the phone first

1. Set a strong device passcode

   Open Settings → Face ID & Passcode, or Touch ID & Passcode on a supported model. Under Passcode Options, consider a custom numeric or alphanumeric code.

2. Choose a suitable Auto-Lock time

   Open Settings → Display & Brightness → Auto-Lock. The device passcode enables iPhone Data Protection, but it does not add a separate password to every document.

Apple instructions: set a passcode on iPhone.

Lock an app when needed

On iOS 18 or later, touch and hold a supported app’s Home Screen icon, choose Require Face ID—or the equivalent Touch ID/passcode wording—and confirm. This is useful when lending someone an already unlocked phone. It does not attach a password to files exported from the app, and some built-in apps cannot be locked. Apple’s app-lock guide.

Use the built-in option for one photo, PDF or note

Photos

Open a photo, choose More → Hide and confirm. The Hidden collection is locked by default using Face ID, Touch ID or the device passcode. With iCloud Photos, hiding also applies on connected devices; the photo remains part of the Photos library. Apple’s Hidden collection guide.

PDFs on iOS 26 or later

1. Open the PDF in Preview.
2. Open the actions menu beside its filename and choose Lock.
3. Enable Require Password if shown, enter and verify a password, then choose Done.
4. Close and reopen the saved document to check it.

Existing unprotected duplicates remain separate copies. Apple’s PDF-lock instructions.

Notes

A short note can use the device passcode or a custom Notes password, but Notes is not a general file locker. Apple excludes notes containing PDFs, video, audio or other file attachments, and the note title remains visible. Apple’s locked-notes guide.

Use Vault for a mixed-file library

Vault is designed for regular documents, images and other files kept together in an encrypted local library. Version 1.0 is coming soon.

1. Import a copy

   Choose Files or Photos. Import leaves the original at its source.

2. Choose optional authentication

   Turn on Settings → Require authentication to open Vault if you want another system check. It starts off for a new vault.

3. Check the imported file

   Open it before changing any source copy.

4. Create and check a recovery backup

   Save the encrypted backup outside the phone and keep its code separately.

Before relying on any method

• Check for other copies in Mail, Downloads, Files, Photos or cloud storage.
• Test with a harmless file first.
• Verify that you can reopen the protected copy.
• Keep a recovery method you can reach if the phone is lost.
• Remember that export creates another ordinary copy unless the file or package is separately encrypted.