How to install wallpaper on the lock screen Xiaomi Redmi Note 9: official and hidden ways

Why the Standard Way Doesn't Always Work and What to Do

The lock screen of the Xiaomi Redmi Note 9 is the first thing you see when you turn on a smartphone, and its design can dramatically change the perception of the device. However, many users find that the wallpaper on the lock is either not installed through standard settings or reset after rebooting. The reason lies in the peculiarities of the MIUI shell: since version 12, Xiaomi has tightened security policies by restricting access to system folders where background images are stored.

In this article, we will discuss three working methods for installing wallpaper on the lock screen – from the official (via the “Themes” app) to hidden functions. MIUI, You'll also learn how to circumvent system limitations if wallpapers fly off after the update, and which third-party apps are safe to use for customization. 9 (model M2003J15SC/M2003J15SS) on MIUI 12–14, But most methods are suitable for other Xiaomi devices on the same firmware.

Before you start, check the MIUI version: go to Settings → About Phone → MIUI version. If you have a version below 12.0.3, some methods may not work – you will need an update.

Method 1: Official method through the "Themes" app

The easiest and safest way to do this is to use the built-in Themes app, which allows you to install both ready-made wallpaper from Xiaomi’s collection and upload your images, but there’s a caveat: not all custom images can be applied to the lock screen due to resolution and format constraints.

To avoid problems, follow the algorithm:

1. Open the “Themes” app** (the icon with a brush on your desktop).
2. Go to the wallpaper tab** in the lower menu.
3. Click on the + icon (or My Wallpaper) → select Local.
4. Select the desired image from the gallery and click "Apply"**.
5. In the window that appears, select Lock Screen Only (or Lock Screen if the interface is in English).

If the "Apply" button** is inactive or the image is cropped incorrectly, then its resolution does not meet the MIUI requirements.

⚠️ Note: If the wallpaper on the lock is blurred after application, check if the Settings function is enabled → Display. → Colours and contrast → Saturation: At 100% above, the system automatically reduces the clarity of background images.

Cut to 1080×2340 | Convert to JPEG/PNG| Check the file size (≤5 MB) | Turn off saturation in display settings

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Method 2: Hidden MIUI function – manual replacement via file system

If the Themes app doesn't allow you to use lock wallpaper, you can use the hidden method by replacing system files, which requires access to the file system, but doesn't need root rights. Importantly, back up your current wallpaper before you start!

Instructions:

1. Connect Redmi Note 9 to your computer via USB (File Transfer Mode).
2. Open the device’s internal memory and go down the path: MIUI → theme → wallpaper If there is no MIUI folder, turn on the display of hidden files in the file manager settings.
3. Copy your image into this folder. Rename it to lockscreen_wallpaper.jpg (for JPEG) or lockscreen_wallpaper.png (for PNG).
4. Reboot the phone. The new wallpaper will apply automatically.

If the wallpaper folder is missing, create it manually, and note that after the MIUI update, the system wallpaper may reset, in which case repeat the procedure.

⚠️ Note: Do not replace files in the theme folder with images with higher resolution 1080×2340. This can lead to a lock animation freeze or a com.android.systemui error.

Method 3: Third-party applications – when standard methods don’t work

If none of the above methods worked, third-party apps will come to the rescue, and we tested 5 popular utilities for customizing the lock screen and selected the two most reliable for the Redmi Note 9:

• 📱 Wallpaper Carousel – automatically changes the wallpaper on the schedule, supports 1080×2340 Plus: Google Photos integration. Minus: requires permission to access notifications.
• 🎨 KLWP Live Wallpaper Maker, which allows you to create dynamic wallpaper with animation, suitable for advanced users, plus: full customization. Minus: high battery consumption.

To install wallpaper through Wallpaper Carousel:

1. Download the app from Google Play.
2. Open it and select “Lock Screen”** in the settings.
3. Upload your image or select from the gallery.
4. Click Set Wallpaper and confirm your choice.

Critical nuance: after installing wallpaper through third-party applications, turn off battery optimization for them in the MIUI settings (Settings → Applications → Application Management → Battery Optimization), otherwise the wallpaper will reset in a few hours.

adb shell pm disable-user --user 0 com.miui.miwallpaper

After that, third-party utilities will receive priority.

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Problem Solving: Wallpapers are dropped or not applied

A frequent complaint of Redmi Note 9 users is that the wallpaper on the lock screen is reset after a reboot or update. This is due to the work of the service com.miui.system, which resets user settings when checking the integrity of the system.

• 🔄 Turn off Automatic Optimization: Go to Settings → The phone. → Additionally. → Optimize the system and deactivate the option.
• 📁 Check the access rights to the wallpaper folder: if you used the method with manual replacement, make sure that the file is not blocked (rights rw-r)--r--).
• 🔧 Reset the cache of the “Themes” app**: Settings → Annexes → Application management → Topics → Warehouse → Clear the cache.

If the problem persists, try an alternative method:

1. Install wallpaper through the Themes app, but select Desktop + Lock.**
2. Then manually replace the desktop wallpaper file (it is stored in the same wallpaper folder under the name home_wallpaper.jpg) standard-ground MIUI.
3. Reboot the phone. The system will save the lock wallpaper, as they are now "tied" to the desktop.

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If the wallpaper is reset after the update MIUI, The reason is most often a theme folder reset. Solution: back up the file. lockscreen_wallpaper.jpg Restore it after each update.

Additional tricks: animation, widgets and live wallpaper

The Redmi Note 9 lock screen supports not only static wallpaper, but also dynamic elements:

• 🌊 Live Wallpaper: Use the App 3D Parallax Background for paralax effect. Up to resolution files are supported 1080×2340 frequency 30 FPS.
• ⏱️ Widgets on lock: activate in Settings → Lock screen → Widgets. Watches, weather and notifications available.
• 🎶 Music visualization: in the Themes app, select wallpaper marked “Dynamic”** – they will respond to the music being played.

For the installation of live wallpaper:

1. Download the Live Wallpapers app from Google Play.
2. Select your favorite animation and click “Install on”**.
3. In the list, select “lock screen”** (confirmation may be required via Settings → Apps → Special Access → Wallpaper Installation).

Note that live wallpaper increases battery consumption by 5-10%. To reduce load, limit frame rates in animation settings (optimally 15 FPS).

FAQ: Frequent questions about wallpaper on the lock screen