Redmi 9C series smartphones running on the MIUI shell can slow down over time, a natural process of accumulating temporary files that create applications while in use. Users often notice that the device begins to respond to commands longer, and free storage space disappears rapidly.
Cache cleaning is a safe and efficient procedure to bring back the system's sharpness. Unlike deleting personal data, it only affects business information without erasing your photos, contacts or correspondence. Proper memory maintenance is especially important for models with 32 or 64 GB drives.
In this article, we will discuss all available cleaning methods, from standard system tools to advanced methods through the engineering menu, learn how to distinguish system debris from important files and which applications are better to clean manually.
Why you need to clean the cache on Android devices
Each app installed creates temporary files to speed up its work: browsers save copies of visited pages, social networks save images from the feed, and navigators save maps of areas. Over time, this digital garbage can take up gigabytes of space critical to installing updates.
In addition to space constraints, the overgrown cache can cause conflicts in the operation of programs. If the application is updated but continues to use old temporary data, errors, crashes or interface freezes may occur, regular prevention avoids such situations and ensures the stability of the operating system.
It's worth understanding the difference between app cache and user data. Cleaning the cache removes temporary files, whereas cleaning the data resets the program to "post-installing" state, removing logins and settings. So it's important to know exactly which button you click on the control menu.
⚠️ Before performing any actions with system files, make sure you have an up-to-date backup of important data on a cloud server or computer.
There are several levels of cleaning: surface (through a standard cleaner), selective (for specific programs) and deep (through Recovery).The choice of method depends on how serious problems you see in the Redmi 9C. In some cases, it is enough to simply restart the device to optimize the processes.
Use of the built-in Security application
The easiest and safest way to free up space is to use Xiaomi’s regular tool, which is pre-installed in the system and has access to all the memory parts it needs, and automatically scans the device for junk files.
Run the program through the main screen or tool folder. On the main page, you will see a "Clean up" button showing the amount of debris you find. Click on it to start the analysis process. The system will check the cache of applications, remnants of deleted programs and temporary files.
Once the scan is complete, a list of file categories that can be deleted will appear on the screen. A standard cleaner usually suggests removing:
- 🗑️ Cache of installed applications (safe to remove).
- 📦 Residual files of remote programs.
- 📸 Duplicate photos (requires manual verification).
- 📂 Large files take up a lot of space.
Click the "Clean" button to remove selected items. The process will take a few seconds. It is important to note that a standard cleaner does not always find all the hidden debris, as some Android system restrictions prevent it from deleting certain temporary files of running processes.
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Use the "Accelerate" function in the same application Security immediately after cleaning the cache - this will close the background processes and free up RAM.
Manually cleaning the cache of specific applications
Often, one particular application, such as YouTube, Telegram or Instagram, causes problems, and these programs tend to accumulate huge amounts of media cache, and to fix the problem point by point without removing the extra one, you need to use the settings of a particular application.
Go to the Settings menu on your smartphone. Find the Apps section and select All Apps. In the list that opens, find a program that consumes a lot of memory (usually the space is displayed immediately).
In the properties menu, look for the Warehouse button, and you'll see two basic options here: Clear cache and Clear everything. Choose cache cleanup, which is safe and doesn't require re-authorization.
☑️ Check before manual cleaning
If the app continues to malfunction after cleaning the cache, you can try a more radical method, which is to clean the data, but remember that this action will delete all your internal settings, saved passwords and correspondence history (if they are not synchronized with the server).
⚠️ Attention: Clearing the data of messengers (WhatsApp, Viber) without prior backup will lead to irretrievable loss of correspondence history!
Cleaning through Recovery Mode
Recovery Mode is an Android diagnostic environment that allows you to perform maintenance at a low level, which is most effective when the phone is slow or not loading correctly, and allows you to clear the system cache (Dalvik/ART Cache), which is not available during normal operation.
To enter recovery mode on Redmi 9C, you need to turn the device off completely. Then press the volume button and the power button at the same time. Hold them until the Mi logo appears, then release the power button, keep the volume up. A menu with a black background will appear on the screen.
Navigation in this menu is done by the volume buttons (up/down), and the choice is confirmed by the power button. You need to find the Wipe data or Wipe cache partition (names may vary depending on the version of MIUI).
| Action. | What's removed | Impact on data | Risk |
|---|---|---|---|
| Wipe Cache | Temporary system files | Data is retained | Low. |
| Wipe Data | All user data | Full reset (as new) | High-pitched |
| Reboot | Nothing. | System restart | No. |
| Connect MI Account | Nothing. | Account binding | No. |
After selecting a cleanup point, the system will ask you to confirm the action. You usually need to choose Confirm or Yes. The process will take a few minutes. Upon completion, select Reboot to start the system as normal. The first boot may take longer than usual.
What to do if the Recovery menu is in Chinese?
Features of cleaning in MIUI 12 and new
The MIUI shell on the Redmi 9C has its own memory management features. In versions 12 and above, the background process algorithms have been changed to improve autonomy, which has led to standard cleaning methods being able to work differently than on pure Android.
Newer versions of the firmware have introduced a feature called "Memory Extension," which uses part of the internal drive as RAM, and if this function is activated, cache cleaning can occur more often, as the system actively uses virtual swap. You can check the status in the section Additional → Expansion of memory.
Also, MIUI has a hidden developer menu where you can customize your caching behavior. To log in, you need to click on the build number several times in the About Phone section. In the developer menu, find the Background Process Limit. The restriction setting can help if the phone is old and has little RAM.
Users should be aware that aggressive background cleaning in MIUI sometimes causes notifications from messengers to arrive with a delay, so after cleaning the cache, it is recommended to give the system 10-15 minutes to stabilize the background services.
⚠️ Note: Do not install third-party accelerators from the Play Market on the MIUI. They conflict with the built-in optimization system and can drain the battery faster.
Automation and useful maintenance tips
So you can set up automatic scripts to avoid manual cleaning every day, and the Security app has a "Schedule Cleanup" setting, activate it by selecting the "Daily" or "Once in 3 days" frequency, which will keep the system in good shape without you.
You should pay special attention to messengers. Telegram and WhatsApp have their own memory usage settings. On Telegram, go to Settings → Data and memory → Memory Use. Here you can set the autodeletion of the cache in, for example, 3 days or a week, this will free up gigabytes of space.
Check the Downloads folder regularly. Often, APK installation files, forgotten documents, and unwanted images get into the folder. The MIUI file manager allows you to sort files by size, which helps you quickly find heavy objects.
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Regularly cleaning the messenger cache through their internal settings is more effective than general cleaning of the system, as it frees up the most space.
If the phone continues to run slowly after all the procedures, it may not be the cache that is the problem, but the wear and tear of the drive or the lack of physical RAM for today’s heavy applications, in which case it is worth considering resetting to factory settings with complete deletion of data.