Memory cleanup on Xiaomi Redmi 9 and other smartphones: from cache to system files

The internal memory of the Xiaomi Redmi 9 (like other Redmi or POCO models) has a nasty feature: over time, it gets clogged with unnecessary files, even if you do not install new applications. The reasons are diverse, from automatically downloadable updates to a messenger cache that can take up gigabytes. When free space approaches the 1-2 GB mark, the phone starts to slow down, applications fly out, and the system warns “Insufficient memory for normal Android operation”.

The problem is compounded by the fact that MIUI (Xiaomi's shell actively uses internal storage for its needs: backups, log files and even duplicate photos from the Mi Cloud are stored here. 7 proven methods of memory cleaning - from basic (hand-held garbage removal) to advanced (hidden developer settings and ADB-All methods tested on Redmi 9/9A/9C/9T, But it is also suitable for other Xiaomi smartphones MIUI 12–14.

1. Analysis of occupied space: what exactly eats memory?

Before you clean it, you need to figure out which files take up the most space. MIUI has a built-in storage analyzer, but it doesn't always show the full picture. Here's how to get accurate data:

1. Open the settings → About the phone → Storage.
2. Slip on the graph "Occupied" - the system will show the distribution by category (applications, multimedia, cache, etc.).
3. For detailed analysis, use third-party utilities like Files by Google or SD Maid (available in the Play Market) to find duplicate photos, large files, and remnants of deleted apps.

Typical memory eaters on Redmi 9:

• 📸 High-resolution photos and videos (especially if the camera shoots at 48 MP). 4K weight ~500MB.
• 🎮 Games (such as Genshin Impact or Call of Duty Mobile) with cache up to 3–5 GB.
• 🗑️ System cache (/cache and /data/dalvik-cache) — before 1–2 GB.
• 📥 Downloads: APK-files, documents, archives that have been downloaded "just in case».
• 🔄 Remains after updates (MIUI Keeps old versions of the firmware in the folder /cache/ota).

⚠️ Note: If the System section is more than 10-12 GB (on Redmi 9 with 64 GB of memory), this may indicate an error in the storage markup after the update.

2. Cleaning the application cache and system

Cache speeds up software, but eventually it turns into digital junk, and on Redmi 9, it can be removed in two ways:

Method 1: Clearing the cache for individual applications

1. Go to Settings → Applications → Application Management.
2. Select an app (such as Facebook or Telegram) → Storage → Clear cache.
3. For mass cleaning, use the Clear Cache for All button (available in some versions of MIUI).

Method 2: Clean the system cache through Recovery

This method removes temporary files from the entire system, including update remnants, and is suitable if the phone has slowed down after installing a new version of MIUI.

1. Turn off your smartphone.
2. Press the Power button + Volume up to enter Recovery Mode.
3. Select a language, then go to Wipe & Reset → Wipe Cache.
4. Confirm the action and restart the phone.

Charge your phone at least 50%

Backup of important data

Remember the password from the Mi-account (required after the reboot)

Do not interrupt the cleaning process-->

After this procedure, Redmi 9 can boot longer than usual (up to 5-10 minutes) – this is normal, since the system recovers the cache again.

3. Delete unnecessary files and duplicates

Even if you clean the gallery regularly, your smartphone still has hidden photos, temporary files and messaging apps, and here's how to find them:

Folders that can be safely cleaned

For convenience, use a root file manager (such as Solid Explorer or FX File Explorer) that shows hidden folders and allows you to sort files by size.

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MIUI has a built-in tool for finding large files: open the Files app → Categories → Large files. Here you can sort media by size and remove unnecessary ones.

How to find and remove duplicate photos

When you transfer photos from other devices or sync with Google Photos/Mi Cloud, you often create duplicates to detect them:

1. Install the Duplicate Files Fixer app or Files by Google.
2. Run scanning of DCIM, Pictures and Download folders.
3. Remove duplicates by leaving the best quality copies.

⚠️ Note: Do not delete files from the folder Android/obb manually, it can break games. To clean them, use the settings of a particular application in Settings. → Annexes.

4. Data transfer to SD-map

If Redmi 9’s internal memory is full and you don’t want to delete anything, transfer your files to an external drive or to the cloud.

Method 1: Use of the SD-maps as internal memory

Redmi 9 supports Adoptable Storage, which allows you to combine the» SD-Important: After that, the card can't be retrieved without losing data!

1. Put it in. SD-map (class recommended) UHS-I or A1/A2 speed).
2. Go to Settings. → Warehouse → SD-map.
3. Tap “Tune in” → “Inner Memory” → “Clean and Format.”
4. After formatting, select “Transfer Data” (photos, videos, some apps).

Method 2: Automatically upload photos to the cloud

Google Photos and Mi Cloud allow you to free up space by saving copies of photos online.

• 📁 Google Photos: Open the app → Profile → Backup settings → Turn on "Backup and Sync." Select "High (unlimited)" quality to save space.
• ☁️ Mi Cloud: Settings → Mi Cloud → gallery → Turn on sync. Please note that there's only 5GB available for free.

Once you upload photos to the cloud, you can delete them from your phone, leaving only thumbnails. Google Photos does this: Photos → Select → Delete from your device.

5. Removal of pre-installed applications (bloatware)

MIUI is known for its abundance of built-in applications that can't be removed by standard means, which take up space and run in the background, using up battery life. Here's how to get rid of them:

Method 1: Disconnection through settings

This won’t delete apps completely, but it will stop them from working and free up some of the memory:

1. Go to Settings → Applications → Application Management.
2. Select an unneeded app (e.g. Mi Pay, Mi Video, Browser).
3. Tap "Disable" → "Disable the application".

Method 2: Complete removal via ADB (for advanced)

If you have a PC and a USB-Type C cable, you can uninstall system applications without root rights:

1. Turn on Developer Mode (Settings → About Phone → MIUI Version → Tap 7 times).
2. Activate USB Debugging in Settings → Additional → For developers.
3. Connect your phone to your PC, open Command Prompt (Windows) or Terminal (Mac/Linux) and type:

adb shell


pm uninstall -k --user 0 com.miui.videoplayer # Deletes Mi Video




pm uninstall -k --user 0 com.miui.browser # Removes Mi Browser




pm uninstall -k --user 0 com.xiaomi.payment # Removes Mi Pay

A full list of removal packages can be found on the 4PDA or XDA Developers forums (see Redmi 9+ “deblot” model).

⚠️ Warning: Removing system applications may disrupt the work MIUI. For example, deleting com.android.cts.ctsshim will cause errors in Google services. Always back up before doing so!

6.Reset to factory settings (last chance)

If nothing works, and the memory is still full of no one knows what, you'll have to do a hard reset, which will delete all the data, including accounts, photos and apps, so first:

• 🔄 Make a backup copy through Settings → Additionally. → Backup and reset.
• ☁️ Sync your contacts with Google or Mi Cloud.
• 📁 Save the photos on your PC or SD-map.

Resetting instructions:

1. Go to Settings → Additional → Backup and Reset → Reset settings.
2. Select “Erase all data” and confirm the action.
3. After the reboot, the phone will be like new. Don't restore the backup right away - check first if the memory problem has returned.

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Resetting to factory settings is the only way to remove memory markup errors that sometimes occur after MIUI updates. If the free space returns after the reset, the problem was with the system files.

7. Prevention: how to prevent memory filling?

To avoid cleaning Redmi 9 every month, follow these rules:

• 📵 Limit the cache for social networks: in Facebook, Instagram and Telegram, turn off autoloading media files.
• 🔄 Set up automatic cleaning: in Settings → Warehouse → Cleaning up garbage, turn on “Autocleaning».
• 🎮 Move the games to SD-Map: In Play Market, select “On” SD-map.
• 📥 Delete. APK After installation: files with the.apk extension in the Download folder can be safely erased.
• 🔍 Check “Other” files: in the storage analyzer (Settings) → Warehouse) Pay attention to the “Other” section – unnecessary data is often hidden here.

It is also useful to reboot your phone in Safe Mode every 2-3 months (press the power button → “Reboot in Safe Mode”). In this mode, only system applications work, and you can see if some third-party software is clogging the memory.

FAQ: Frequent questions about memory cleanup on Xiaomi