How to put a password on the application in Xiaomi Mi 9: all ways to protect

Protecting personal data on Xiaomi Mi 9 is a challenge that gets more and more relevant every year. Even if you don’t hand over your phone to outsiders, random access to instant messengers, banking apps or social networks can lead to leakage of sensitive information. Fortunately, MIUI firmware offers several built-in mechanisms for blocking applications, and for advanced functions you can use third-party solutions.

In this article, we will discuss three working ways to set a password for applications in Xiaomi Mi 9 (relevant to MIUI 12, 13 and 14), including hidden system features that many users miss. You will learn how to configure security through Security, use Second Space for full application isolation, and which third-party programs are reliable and do not slow down the smartphone.

1. Built-in application locking through "Security"

The easiest and most reliable way to do this is to use the built-in MIUI feature, which does not require superuser rights and works at the system level, which is suitable for blocking individual applications (such as WhatsApp, SberBank Online or galleries) without installing additional software.

To activate the protection:

• 📱 Open the Settings menu → Passwords and security → Application lockdown.
• 🔒 If the function is disabled, the system will prompt you to install a pattern lock, PIN-Choose a convenient option (we recommend a combination of 6)+ figure).
• 📌 In the list of applications, mark the ones you want to block. For convenience, you can use the search by name.
• ⚙️ In the additional settings (⋮ → Lock options) enable the “Hide Notifications” option so that the content of messages does not appear on the locked screen.

Important: Once you activate the lock, the app will require you to enter a password at each launch, even if the phone is already unlocked. This may seem inconvenient, but it guarantees maximum protection. If you need to temporarily disable the check (for example, at home), use Trust Mode in the same settings - it allows you to unblock certain Wi-Fi networks.

Set up a reliable one. PIN-code (not date of birth)|Download a backup copy of important data|Check the fingerprint work|Disable Auto-Run of Blocked Applications-->

2.Second Space: Complete Application Isolation

The MIUI’s Dual Apps feature is originally designed to clone messengers, but it can be adapted to protect sensitive data, and the method is that you transfer sensitive applications to a separate profile with a password that looks no different from the main desktop.

How to set up:

1. Go to Settings → Special Opportunities → Second Space.
2. Create a new profile by following the instructions (you will need to come up with a separate PIN or pattern lock).
3. After creation, go to the second space through the notification panel (icon) 👤).
4. Install the desired applications (they will be duplicated from the main profile) and configure them.
5. Return to the main space – now blocked applications will be available only after entering the password of the second profile.

The advantage of this method is that the applications in the second space are completely isolated from the main system, including notifications and background processes. For example, if you block Telegram in this way, messages will not appear in the main profile, and only someone who knows the password of the second space will access the chats.

Built-in lock through "Security"|Second space|Annex side (AppLock)|Don't use protection.-->

3. Third-party applications: AppLock and analogues

If the built-in MIUI features are not enough (for example, you need to block system utilities or configure an access schedule), you can use third-party programs.

• 🔐 AppLock (from DoMobile Lab) – supports locking by fingerprint, face and PIN-code, there is a function "Invisible mode" (the app icon is hidden).
• 🛡️ Norton App Lock is a reliable solution from the well-known antivirus, integrates with other Norton products.
• 📱 Smart AppLock – allows you to block not only applications, but also individual functions (for example, mobile data or Wi-Fi).

Warning: Check the app permissions before installing. Some AppLock programs request access to Notices and Special Features, which can be used to collect data.

⚠️ Attention: Xiaomi Mi 9S MIUI 14 Some third-party blockers may conflict with system memory optimization. If applications start to spontaneously close after installing AppLock, add the blocker to the autoclean exception list (Settings) → Annexes → Auto-start).

4. Hidden Opportunities: Blocking through ADB (for Advanced)

If you're willing to use a developer tool, you can block applications at the system level without third-party software, which requires PC connectivity and ADB commands, but gives you maximum control.

Instructions:

1. Activate Developer Mode on Mi 9: Go to Settings → About Phone and click on MIUI Version 7 times.
2. Enable USB debugging in Settings → Additional → For developers.
3. Connect your phone to your PC, install ADB drivers, and open the command line.
4. Enter the command to lock the application (e.g. Gallery): adb shell pm hide com.miui.gallery To unlock, use: adb shell pm unhide com.miui.gallery

This method hides the application from the menu and search, but does not delete its data. To return access, you will need to re-enter the command or reset settings through ADB. The method is suitable for system utilities that cannot be blocked by standard means (for example, com.android.settings - phone settings).

Frequent problems and their solutions

When setting up a lock on Xiaomi Mi 9, users encounter typical errors, and here are the most common ways to fix them:

• 🔄 Password is not requested after rebooting: check if the option to Request Password after restarting is enabled in the lock settings. MIUI 14 It may be reset after updates.
• 📵 The fingerprint doesn't work: delete all the fingerprints you saved and add them again. On the Mi 9, the scanner sensor wears out over time -- try registering your finger at a different angle.
• 🚫 AppLock does not block applications: add the program to Battery Optimization Exceptions (Settings) → Battery → Optimizing the battery).
• 🔍 The app disappeared after being blocked through ADB: Use the adb shell pm list packages command -d, To see the list of hidden packages, then unlock the desired package.

⚠️ Note: If you use the Second Space and forget your password, you can only restore access through a full reset (Settings) → Resetting settings). MIUI It does not provide alternative ways to unlock the second profile, so write down the PIN-safe-code.

Alternative methods of protection

In addition to blocking applications, the Xiaomi Mi 9 can use additional security measures:

• 🔐 Phone Encryption: Activated in Settings → Passwords and security → Phone encryption slows down by 5 to 10 percent, but makes data unavailable without a password even when connected to a PC.
• 📁 Hidden folders: in the standard Explorer MIUI You can create a folder with a dot at the beginning of the name (for example,.private) - it will be hidden from prying eyes.
• 🔄 Automatic lock: set up settings → Lock screen → Autolock for a minimum of 5 seconds to keep your phone locked right after sleep.

For maximum protection, combine several methods, for example, you can block SberBank through the built-in MIUI function, transfer Telegram to the Second Space, and hide system settings through ADB. So even if a password is leaked from one method, the remaining layers of protection will remain intact.

💡

If you often pass your phone to colleagues or children, create a guest profile in Settings → System → Multiple users, which will only access basic applications (calls, camera), and personal data will remain hidden.

FAQ: Answers to Frequent Questions

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On the Xiaomi Mi 9, the most reliable way to block is a combination of Second Space for Critical Applications and the built-in App Lock for Others. Third-party programs are convenient, but can conflict with MIUI optimization.