How to install wallpaper on the lock screen Xiaomi Redmi 9: all working ways

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

The lock screen Xiaomi Redmi 9 is the first thing you see when you turn on the smartphone, but not all users know that it can be customized deeper than what offers. MIUI Unlike desktop wallpapers, which change in two clicks, the background of the lock screen often ignores attempts to replace through the standard menu. MIUI: the system limits the change of the background lock to protect against phishing (for example, scammers could fake the input screen) PIN-code).

But you can get around this limitation -- and you don't have to get root rights or install custom firmware. In this article, we'll look at 5 proven ways, including hidden MIUI features, third-party apps, and even ADB commands for advanced users. Importantly, some methods require developer mode activation, but we'll explain in detail how to do this without risking the system.

If you’ve previously tried to change the background through Settings → Lock screen and received the message “You can’t change the wallpaper on this device”, don’t be too upset. Most likely, your Redmi 9 is running MIUI 12/13 with updated restrictions. Below you will find solutions that are relevant for all firmware versions, including the latest updates from 2026.

Method 1: Standard Replacement by MIUI-The launcher (not working on all versions)

The most obvious method is to use built-in MIUI tools, which will work if your Redmi 9 runs on firmware older than MIUI 12.5, or if the manufacturer has not blocked this feature for your region.

1. Open the Themes app (icon with brush and palette).
2. Go to the section My wallpaper → Lock screen.
3. Select one of the suggested pictures or click Add Wallpaper to upload your image.
4. Confirm the choice with the Apply button.

If the background is unchanged after this action, then your version of MIUI is blocking editing, in which case move on to the following ways.

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Before loading your wallpaper, trim the image in a ratio of 1080×2340 pixels (Redmi 9 screen resolution).

⚠️ Note: Some wallpapers in the Themes section may automatically apply animations or widgets (such as a watch) that eat up to the top of the list. 5-7% Turn them off in the lock screen settings if you notice a quick discharge.

Method 2: Using Google’s Wallpapers app

Google’s official Wallpaper app (available on the Play Market) allows you to bypass the limitations of MIUI and install any image on the lock screen.This method works on Redmi 9 with MIUI 11 and newer, but requires a little preparation:

• 📱 Install the Wallpapers app from Google.
• 🖼️ Select My Photos Category and upload the desired image.
• 🔒 At the application stage, click Set the Lock screen (not the desktop!).
• ⚙️ If the background hasn't changed, reboot the phone - sometimes MIUI caching old settings.

The advantage of this method is access to Google wallpaper collections, including live wallpapers (such as Earth or Landscapes), which automatically adjust to the time of day, but note that animated background images can increase battery consumption by 3-5%.

Download the app from the official store | Cut the image to screen resolution | Turn off battery optimization for the app |Reboot the phone after application-->

Method 3: Hidden MIUI function through the theme editor (for advanced)

MIUI has a hidden tool for deep customization of the interface, the theme editor, which allows you to change not only wallpaper, but also icons, fonts, animations, to use it:

1. Activate Developer Mode: Go to Settings → About Phone and click on MIUI Version 7 times.
2. Return to Settings → Additional → For developers and enable USB debugging.
3. Install the MIUI Theme Editor app (available on Chinese forums, such as CoolAPK).
4. In the editor, select Lockscreen → Wallpaper and upload your image.

This method offers maximum freedom, but has risks: informal theme editors may contain malicious code. Use only verified sources and disable debugging via USB after setting up.

Method 4: Change wallpaper through ADB (without root)

For those who are not afraid of the command line, there is a reliable method using Android Debug Bridge (ADB). It does not require superuser rights, but it does require a computer and USB-Here's the step-by-step instructions:

1. Download and install ADB Tools on PC.
2. Connect Redmi 9 to your computer and allow debugging over USB.
3. Open the command line (or Terminal) Mac/Linux) Enter: adb shell settings put global lock_screen_wallpaper /sdcard/your_wallpaper.jpg Replace. your_wallpaper.jpg The way to your image (it should be in the memory of the phone).
4. Reset the device.

If the background hasn’t changed after the reboot, try an alternative command:

adb shell am broadcast -a android.intent.action.SET_WALLPAPER -e mimeType image/jpeg -e uri file:///sdcard/your_wallpaper.jpg

⚠️ Attention: Some versions MIUI They reset the lock screen wallpaper after the system update. To avoid this, back up the image in the cloud (like Google Photos) and reapply it after the update.

Method 5: Third-party applications (with caution!)

There are dozens of apps in the Play Market that can change the lock screen wallpaper, but most of them either don't work on MIUI or require root rights. We tested three reliable options:

• 🌄 Wallpaper Carousel – automatically changes the background on a schedule, supports Redmi 9 on the MIUI 12–14.
• 🔒 Lock Screen Wallpaper Changer – specializes in lock screens, but can conflict with system wallpaper.
• 🖼️ Muzei Live Wallpaper – allows you to use live wallpaper even on a locked screen (requires manual settings).

Check reviews before installing: some apps display ads on the lock screen or collect user data. Avoid programs that request access to SMS, contacts or geolocation - these are unnecessary permissions for changing wallpaper.

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Third-party apps can conflict with MIUI system wallpapers. If the background flashes or disappears after installation, uninstall the app and use ADB or Google Wallpapers.

Frequent problems and their solutions

Even after a successful wallpaper change, Redmi 9 users are plagued with bugs, and here are the most common ways to fix them:

• 🔄 Background resets after reboot: This is a feature MIUI. The solution is to use ADB to fix wallpaper (see Method 4) or disable automatic optimization in battery settings.
• 🖼️ Image cropped or stretched: Check the resolution of the picture. for Redmi 9 optimally 1080×2340 Use an editor (e.g. Photoshop Express) to crop.
• ⚡ Fast battery discharge: Live wallpaper or animations on the lock screen can consume up to 10% of charge per night. → Lock screen → Additionally.

If none of these methods worked, check to see if your device has a corporate policy set (e.g., Microsoft Intune or MobileIron), which often blocks changes to system settings.

FAQ: Answers to popular questions