Cache Cleanup on Xiaomi Mi 9: A Complete Guide to Accelerating Your Smartphone

Why does the Xiaomi Mi 9 cache require regular cleaning?

The Xiaomi Mi 9, released in 2019, is still popular with users thanks to its powerful hardware: Snapdragon 855 processor, 6-8 GB of RAM and 128 GB of internal storage. However, even these features do not save the problem of Android devices — cache clogging. Over time, the phone begins to “brake”, applications open longer, and the battery goes down faster.

There are two types of cache: system (created) MIUI To speed up the interface, and to cache applications (time data from games, instant messengers, browsers). With the Mi 9, with its limited memory (compared to today's flagships), cache cleaning becomes not a luxury, but a necessity. For example, the cache of Google Play Services can weigh up to 1-2 GB, and social networks like TikTok or Instagram – up to 500 MB each. MIUI It doesn’t always delete all temporary files, some of them remain in hidden folders.

In this article, you will find 5 working ways to clean the cache, from basic (through the settings menu) to advanced (using ADB and third-party utilities), we will also discuss how to clean the cache of individual applications without affecting user data, and what to do if after cleaning the phone began to work even worse.

Method 1: Clearing the cache through MIUI settings

The easiest and safest method is to use the built-in MIUI tools, which are suitable for beginners and do not require root rights, but keep in mind that this method only clears the application cache, but does not affect the system temporary files.

Instructions:

1. Open Settings (the gear icon on the main screen).
2. Go to the Appendix section → Application management.
3. In the upper right corner, press three dots (⋮) and select Sort by size.
4. Tap on the app you want to clear (such as Chrome or Facebook).
5. Click Clear Cache (not to be confused with Clear Data – it will delete all account settings!).

For mass cleaning:

• 🔍 In the same Application Management menu, swipe right to the Cash tab.
• 🧹 Click Clear Everything (remove the cache of all applications except system ones).
• ⚠️ Note: After this operation, some applications (such as maps or messengers) will load longer than usual when they first start up – this is normal.

Close all background applications

Connect your phone to charge (if the charge is below 30%)

Save important data from apps (e.g. game progress)

Restart the phone after cleaning-->

Method 2: Using the built-in Optimizer

MIUI has a built-in Security tool (formerly Optimizer) that can clean not only cache but also junk files, a method deeper than manually cleaning through settings, as it affects system time data.

How to use:

1. Open the Security app (the shield icon on the desktop).
2. Go to the Cleanup tab (or Garbage in newer versions of MIUI).
3. Wait for the scan to be completed (it may take 1-2 minutes).
4. Click Clear (or select specific file categories to delete).

What removes this tool:

⚠️ Note: If after cleaning through Security, the phone began to restart or lag, check the free space in the Settings section. → Memory. It may be that the system deleted critical files due to space constraints, in which case rebooting or resetting cache via Recovery (more on this below) will help).

Once a week.

Once a month

Only when the phone starts to brake

Never cleaned.-->

Method 3: Cleaning the cache with Recovery Mode (for experienced)

If standard methods don't work and the phone still bugs, you can use Recovery, which clears the partition cache, which is especially useful after MIUI updates or when the system is running faulty, but it requires caution: improper actions in Recovery can cause the phone to reset to factory settings.

Step-by-step:

1. Turn off the Xiaomi Mi 9.
2. Press the Power + Volume buttons up at the same time and hold for 10-15 seconds until the Mi logo appears.
3. Release the buttons – you will be taken to the Recovery menu (management is carried out by the volume and power buttons).
4. Select Wipe & Reset (or Wipe Cache in newer versions).
5. Confirm the action by selecting Wipe Cache Partition.
6. After you complete the process, select Reboot to System.

⚠️ Warning: Do not choose Wipe Data or Factory Reset, it will result in a complete reset of the phone! Also do not interrupt the cleaning process (even if it took more than 5 minutes, TWRP) The menu may look different, but look for Advanced Wipe. → Cache.

Method 4: Manually clean the cache through the file manager

For those who aren’t afraid to dig through system folders, there’s a way to manually clean the cache, which allows you to delete files that aren’t visible through standard settings, such as the Google Play Services cache or remnants from remote applications, but it will require a file manager with root rights (like Root Explorer or FX File Explorer) or at least access to hidden folders.

Where to find the cash:

• 📁 /data/data/ — It stores the caches of all installed applications (folders with names like com.android.chrome).
• 📁 /cache/ — System cache (cleaned only through Recovery).
• 📁 /sdcard/Android/data/ — cache of games and heavy applications (for example, PUBG Mobile or Genshin Impact).
• 📁 /sdcard/DCIM/.thumbnails — Photo and video miniatures (can be removed without consequences).

⚠️ Note: Delete only files inside cache folders! Delete other files (such as lib or databases) will lead to the collapse of the application. SD Maid (requires root).

💡

Before manually clearing the cache, back up important folders (e.g. /sdcard/WhatsApp/Databases) as some apps store temporary chat or media data in the cache.

Method 5: Advanced Cleaning through ADB (for developers)

If you're familiar with Android Debug Bridge (ADB), you can clear the cache of all applications with one command, which is useful when standard methods don't work (for example, due to a failure in MIUI), which requires a computer with Xiaomi drivers installed and enabled USB debugging on the phone.

Instructions:

1. Turn on Developer Mode on Mi 9: go to Settings → About Phone and tap the MIUI version 7 times.
2. Return to Settings → Additional → For developers and activate Debugging over USB.
3. Connect your phone to your PC, open the command prompt (Windows) or terminal (macOS/Linux) and type:

adb devices

(A device with a serial number must appear).

1. Run a command to clean the cache of all applications:

adb shell pm trim-caches 999999999G

Or to clean the cache of a particular app (like Facebook):

adb shell pm clear com.facebook.katana

⚠️ Note: pm clear removes all app data (including settings and accounts) not just cache:

adb shell run-as com.package.name rm -rf /data/data/com.package.name/cache/*

(Replace com.package.name with the real name of the package)

💡

Cleaning through ADB is the most radical method, but it requires technical knowledge. If you are not sure about the commands, it is better to use standard methods or third-party utilities.

What if after cleaning the cache, the phone becomes worse?

Sometimes, after a mass cache clearing, users experience the opposite effect: the Mi 9 starts to “freeze”, open applications more slowly, or even overheat, which is due to the fact that the system is forced to recreate cache files, which loads the processor.

• ⏳ Wait 12-24 hours. MIUI Optimizes work after cleaning in the background.
• 🔄 Reboot the phone. It'll reset the time processes that might have been hanging».
• 🛠️ Turn off animation. Go to Settings. → For developers and set the scale of animation on the Off. – this will speed up the interface.
• 🗑️ Check the space if the memory is 90 after cleaning the cache%+, Delete unnecessary files or transfer them to the SD-map.

If the problems have not gone away, perhaps the reason is not the cache, but in:

• 🔋 Worn-out battery (check battery health via ##4636##).
• 🤖 Firmware failure (try to update) MIUI through settings → The phone. → Updating the system).
• 🦠 Viruses (scan your phone through Google Play Protection or Malwarebytes).

FAQ: Frequent questions about cleaning the cache on Xiaomi Mi 9