How to completely clean the memory on Xiaomi Redmi Note 9: from cache to deep cleaning

Why is Redmi Note 9 slowing down and what does it have to do with memory?

Owners of Xiaomi Redmi Note 9 often face the problem of lack of memory after 1-2 years of use. Even with 64 or 128 GB of internal memory, the smartphone begins to “gasp”: applications slowly open, photos are not saved, and the system gives a notification “Memory is full.”

The point is that the operating system MIUI It actively uses cache, temporary files and backups, and adds “junk” from messengers (especially Telegram and WhatsApp), duplicate photos in Google Photos, and undeleted ones. APK-For example, one hour of watching TikTok can take up to 500 MB of cache, and Genshin Impact can take up to 8 GB of temporary data.

But not all that bad: Redmi Note 9 can free up to 15-20 GB of memory without deleting personal files, if you know where to look for “garbage”. Below are proven ways from simple to complex, taking into account the features of MIUI 12-14.

Method 1: Cleaning the application cache manually

The fastest method is to remove the cache of individual apps, which will not delete your data (messages, photos, settings), but will free up space occupied by temporary files, for example, YouTube cache can weigh 1-2 GB, and Instagram can weigh up to 500 MB.

How to do this:

1. Open Settings → Applications → Application Management.
2. Slip on the three dots in the upper right corner and select Sort by size.
3. Select an app (like Chrome or Facebook) and click Clear Cache.

⚠️ Note: Do not clear the cache for Google Play Services, MIUI System and Security can cause system failures, and avoid clearing the cache of banking applications (e.g. SberBank Online) as they may require re-authorization.

📷 Instagram (up to 1 GB)

🎵 Spotify (up to 5GB for offline listening)

📺 YouTube (up to 2 GB)

💬 Telegram (up to 3 GB in the folder Telegram Images)

🎮 Games (Call of Duty Mobile, PUBG — 5GB)

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Method 2: Automatic cleaning through “Safety”

MIUI has a built-in garbage cleanup tool called Security (or Security in the global version), which analyzes the system and suggests removing unnecessary files: residual data after uninstallation, empty folders, duplicates and cache.

Instructions:

1. Open the Security app (shield icon).
2. Go to the Cleaner (or Cleaner) tab.
3. Click Scan and wait for the analysis to be completed.
4. Select file categories to delete (we recommend ticking Residual Files, Application Cache, and Large Files).
5. Press Clear.

🔍 Hidden function: B MIUI 14, you have the Deep Clean option, which removes system debris that is not available manually, and to activate it, after scanning, tap the label Deep Clean at the bottom of the screen.

Once a week.

Once a month

Only when memory ends

Never clean.

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Method 3: Removing duplicate photos and videos

One of the main memory eaters on the Redmi Note 9 is duplicate photos and videos.

• 🔄 Automatic backup in Google Photos and Mi Cloud.
• 📸 Filming in mode HDR (The smartphone saves both the original and the processed version).
• 🤳 Send photos via instant messengers (for example, WhatsApp creates copies in the WhatsApp Images folder).
• 🎥 Video recordings in 4K (1 minute = ~400MB).

To find and remove duplicates:

1. Open Gallery → Albums → Duplicates (in MIUI 13/14)
2. The app will automatically group similar photos. Select Delete duplicates.
3. For manual checks, use the file manager: go to /storage/emulated/0/DCIM/ and /storage/emulated/0/Pictures/.

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Before removing duplicates, turn on the hidden files in the file manager (click on three dots → Settings → Show hidden files). Often duplicates are hidden in folders like.thumbnails or.cache.

Method 4: Transfer files to a memory card or cloud

If the Redmi Note 9 has less than 10 percent of the internal memory, the system starts to slow down, so the solution is to transfer heavy files to a microSD or to the cloud.

• 📁 Memory card: Redmi Note 9 supports microSD up to 512GB, but not all apps can be ported (for example, WhatsApp does not work from the card).
• ☁️ Cloud: Mi Cloud gives free 5 GB, Google Photos - 15 GB (but compressed photos.
• ⚠️ Some games (such as Call of Duty Mobile) don’t work with a memory card – they require internal memory.

How to transfer files to microSD:

1. Insert a memory card (FAT32 or exFAT format).
2. Open Files → Categories → Images / Videos.
3. Select files, click More → Move → Memory Map.

⚠️ Note: If you use a card as internal memory (an option when formatting), it cannot be retrieved without losing data. UHS-I U1 lower.

Method 5: Remove System Applications (for Advanced)

MIUI is pre-installed with dozens of unnecessary apps: Mi Pay, Mi Video, GetApps, Browser, and others. They take up space and work in the background, even if you don't use them. You can't uninstall them with standard tools, but there are workarounds.

Option 1: Disconnect (without root)

1. Go to Settings → Applications → Application Management.
2. Select an unused app (such as Mi Music).
3. Click Disable (if the button is active).

Option 2: Remove via ADB (PC required)

It's a method for power users, and it allows you to completely remove system applications without root permissions.

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


adb shell pm uninstall --user 0 com.miui.player # Deletes Mi Music




adb shell pm uninstall --user 0 com.xiaomi.gamecenter # Deletes Game Center

⚠️ Warning: Removing system applications may cause malfunctions MIUI. For example, removing Mi Security (com.miui.securitycenter) will turn off the virus scanner and garbage cleanup.Be sure to back up through Settings before removing it. → The phone. → Backup.

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Do not remove applications with com.android., com.google. and com.miui.system* packages – these are critical components of the system!

Method 6: Reset to factory settings (last resort)

If none of these methods worked, and the Redmi Note 9 has less than 1-2 GB of free memory, you will have to do a hard reset. This will delete all data, including photos, messages and applications, but return the smartphone to the “clean” state.

How to reset your settings:

1. Back up important data (photos, contacts, messages) to your PC or cloud.
2. Go to Settings → About the phone → Reset settings.
3. Choose to erase all data.
4. Enter the password (if set) and confirm the reset.

⚠️ Attention: Redmi Note 9 with MIUI 12-14 after reset, you may need to re-assign your Mi Account. If you forget your password, your smartphone will be locked! Make sure you remember your login and password or untie your account in advance in Settings → Mi Account.

🔄 Alternative: Instead of completely resetting, you can do a Settings Reset without deleting data (the option to Reset Network/Application Settings.

Method 7: Optimize memory for gaming and heavy applications

If you use Redmi Note 9 for games (Genshin Impact, PUBG, Call of Duty Mobile), memory may be scarce even after cleaning.

• 🎮 Cleaning the game cache: In Settings → Apps find the game and click Clear Cache (for example, Genshin Impact can take up to 8 GB of cache).
• 🔄 Background Disconnection: In Settings → Special facilities → Optimize games disable background update for games.
• 📥 Installation to the map: Some games (for example, Asphalt 9) allow you to transfer some data to a microSD. → Memory map.
• ⚡ Performance mode: Enable Game mode in the notification curtain – this will limit background processes.

💡 Tip for gamers: If the game is lagging due to memory shortage, try to reduce the graphical settings in the game itself (for example, in the game). PUBG Select Balanced Mobile instead of Balanced HDR). This will reduce the load on storage and RAM.

FAQ: Frequent Memory Cleanup Questions on Redmi Note 9