How to Clean Xiaomi Redmi 9: From Cache to Deep Cleaning

Xiaomi Redmi 9 is one of the most popular budget smartphones, but over time, even it begins to “brake” because of accumulated system debris, residual files of deleted applications and crowded cache, if your device is slow to work, warm up or discharge quickly, it’s time to do a general cleaning.

In this article, we will look at all the ways to clean Redmi 9, from basic methods (cache removal, memory optimization) to deep cleaning (factory reset, virus removal), focusing on data security: how to keep photos, contacts and other important files safe during cleaning, and learn which cleaning applications really work and which ones take up space.

Important: Procedures differ for different versions of MIUI. This article provides the current instructions for MIUI 12/13/14 (the latest supported version for Redmi 9 for 2026). If you have an older firmware, some menu items may be called differently.

1. Basic cleaning: cache, debris and background processes

Start with simple steps that don’t require you to install additional programs, and even cleaning your cache regularly can get your smartphone back to speed.

Redmi 9 has three types of cache: applications (temporary program files), Dalvik cache (system files to speed up Android), and MIUI cache (shell data), which need to be cleaned in different ways.

• 📱 Application cache: go to Settings → Annexes → App management, select the right one and click "Clear Cache." For mass cleaning, use Settings → Memory. → Cleanup.
• 🔄 Background processes: in Settings → Battery and productivity → Battery management disable auto-run of unnecessary applications, this will reduce charge consumption and free up RAM.
• 🗑️ Garbage files: MIUI It has a built-in cleaner. Run it through Security. → Cleaning (broom icon) You can also delete duplicate photos and large files here.

Note the Memory → Memory Analysis section, where the system shows what exactly is taking up space: apps, media files, documents, or Other (most often residual files of remote programs), if the Other category takes up more than 5 GB, it's time to do a deep cleanup.

Memory Optimization: What Can Be Deleted Without Risk

Redmi 9 has only 32/64GB of memory (depending on the modification), and it gets clogged over time, but not all files can be deleted without consequences, and we'll figure out what's safe to clean and what's not.

Critical Information: Never delete folders MIUI, system or files with extension.odex/.vdex — If you're in doubt, you'd better use the built-in cleaner. MIUI.

For a deep memory analysis, install Files by Google, the official Google app, which will show:

• 📁 Unnecessary files (duplicates, screenshots, old memes).
• 🎮 Large game files (can be transferred to the SD-map).
• 📄 Documents that have not been opened in a long time.

Cash of messengers (Telegram, WhatsApp)

Old ones. APK-files from the Download folder

Logs and dumps of system errors

Game folders that have already been deleted

Duplicate photos and screenshots-->

3. Cleaning system files: when root rights are needed

If the basic methods didn’t work and the smartphone is still slowing down, the problem may be in the system debris, such as residual files after MIUI updates, unnecessary libraries or “battered” application data, which will require root rights or special utilities to delete.

Without root, you can try:

• 🛠️ SD Maid (a system garbage cleaner application, works without root, but with restrictions).
• 🧹 CCleaner (knows how to clean Dalvik cache, but the latest versions have a lot of advertising).
• 🔍 Storage Analyzer (shows heavy folders that can be manually cleaned).

With root rights, opportunities are expanded:

• Remove unnecessary system applications (bloatware) through Titanium Backup.
• Clean /data/dalvik-cache folder (accelerates Android work).
• Remove old cores (boot.img) after updates.

⚠️ Attention: getting root rights voids warranty and can cause a device to break. Redmi 9 uses Magisk, but the process requires unlocking the bootloader, which erases all data!

4. Reset to factory settings: when necessary

If the Redmi 9 is too slow, overheating, or making mistakes, it’s time to do a hard reset, which is a last resort, but it will return the smartphone to its original state.

Before discharge, it is mandatory:

1. Make a backup through Settings → Additional → Backup and Reset → Local Backup.
2. Copy photos and videos to your PC or cloud (Google Photos, Mi Cloud).
3. Take pictures or take pictures of important SMS/notes.
4. Make sure you know the username and password from your Mi Account account – after reset, you will need authorization!

The reset itself is done in two ways: via menu: Settings → Additional → Backup and Reset → Resetting → Delete all data. Through Recovery:

Turn off the phone, press Power + Volume up, and select Wipe Data → Wipe All Data from the recovery menu.

⚠️ Warning: Once reset, Redmi 9 may require you to enter your old password, even if you didn't set it. FRP (Factory Reset Protection If you forget your password, restore it through your Mi Account before resetting!

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Reset to factory settings deletes ALL data, including files on internal memory. SD-The card is not affected, but it is better to remove it before the procedure.

5. Removal of viruses and malware

The MIUI-based Redmi 9 has built-in virus protection, but it's not perfect. If a smartphone starts showing ads in a browser, installing apps spontaneously, or quickly discharging, it's likely infected.

Signs of the virus:

• 📢 Advertising in the status bar or on top of other applications.
• 🔋 Fast battery consumption (check settings) → Battery for suspicious processes).
• 📱 Unknown apps on the menu (often masquerading as “Google Play Services” or “System Update»).
• 🌐 Redirecting in the browser to strange sites.

How to clean:

1. Launch Security → Scanning (built-in antivirus) MIUI).
2. Install Malwarebytes or Dr.Web Light for a deep check.
3. Check Administrator Permits: Settings → Passwords and Security → Device Administrators. Delete suspicious apps.
4. If the virus is not removed, reset your smartphone to factory settings.

A common cause of infection is installing applications from unknown sources. Turn this feature off in Settings → Passwords and Security → Unknown sources.

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If you still have ads after removing the virus, check your browsers for malicious extensions. In Chrome, go to Settings → Additional Settings → Extensions and remove anything suspicious.

6.Optimization after cleaning: how to maintain speed

Cleaning is only half the battle. To keep Redmi 9 from getting polluted again, follow these tips:

• 📵 Turn off auto-start applications: Settings → Battery and productivity → Battery management → Select applications. Leave auto-run only for messengers and important utilities.
• 🔄 Update. MIUI: In new versions, optimized memory. Check the updates in Settings → The phone. → Updating the system.
• 🛡️ Use lighter versions of apps: instead of Facebook, install Facebook Lite, instead of Chrome, Chrome Lite (or Bromite).
• 🗃️ Transfer files to SD-map: photos, videos and music are best stored on an external drive. → Memory. → Default storage select SD-map.

You should also disable unnecessary MIUI features that consume resources:

• Animations: Settings → About Phone → MIUI Version (click 7 times) → Additional settings → Windows Animation (select 0.5x or turn off).
• Secondary spatial sound: Settings → Sound → Sound effects.
• Autosynchronization of accounts: Settings → Accounts → Synchronization.

If you follow these rules, Redmi 9 will work quickly even after 2-3 years of use, the main thing is to prevent the accumulation of garbage and regularly (every 1-2 months) carry out basic cleaning.

FAQ: Frequent questions about cleaning Xiaomi Redmi 9