Redmi smartphones, particularly the 9C, have earned popular acclaim for their availability and reliability, but over time, even the most optimized device can start to run slower. The main reason for the decline in performance and lack of free space is often the accumulated cache of applications and system debris that inevitably forms during the operation of the gadget. Understanding how to manage this data is a key skill for every Android device owner who wants to extend the life of his device.
Unlike a full factory reset that deletes all user data, a competent cache cleaning allows you to free up gigabytes of space without losing photos, contacts or correspondence. Xiaomi Redmi 9C works on the basis of the MIUI shell, which has its own features in memory management, different from stock Android. In this article, we will discuss in detail all available cleaning methods, from regular tools to advanced techniques for advanced users.
Regular file system maintenance not only restores the speed of the interface, but also prevents applications from running errors that can occur due to corrupted temporary files. Many users mistakenly believe that you need third-party programs to clean, but embedded MIUI tools are often more efficient and safer. Let's look at how to properly conduct this procedure.
What is the cache and why does it take up space on the Redmi 9C?
Cache is a region of RAM or permanent memory designed to store temporary files that speed up the loading of frequently used applications and web pages. When you launch YouTube, Telegram or a browser, the system stores logos, video previews and interface elements so that the next time you log in, you don't download them again from the Internet. This saves traffic and processor time, but over time, such "temporary" data can reach several gigabytes.
On budget devices like the Xiaomi 9C, the amount of internal memory is often limited to 32 or 64 gigabytes, of which a significant part is occupied by the system itself. The accumulation of junk files leads to the fact that the empty space ends, and the phone begins to work unstable: applications fly out, the interface slows down, and new programs simply have nowhere to install. It is important to understand the difference between the cache and the application data: removing the first is safe, removing the second will reset the application in the “just installed” state.
Android doesn't delete these files automatically because it thinks they're good for speed, but some software algorithms are not written correctly, and they can inflate the cache to absurd sizes, storing irrelevant information, which is why manual or semi-automatic cleaning is a necessary maintenance procedure.
⚠️ Warning: Don’t confuse cache cleaning with data cleaning. If you choose Clear Data, the app will delete all your logins, settings, and correspondence history inside it, returning to factory status.
Use of the built-in "Security" application
The easiest and safest way to free up space on the Redmi 9C is to use a pre-installed system tool, and in the MIUI shell, this is done by the Security app (green shield icon), which is deeply integrated into the system and has permissions to remove system debris that are not available to third-party utilities. Launch the application and click on the large Speed or Clean button to begin scanning.
After the initial analysis, the system will suggest removing files ranging in size from a few megabytes to gigabytes. It is important to be careful: standard cleaning is usually safe, but before the final confirmation, you better click on the Details or Analysis button to see what exactly will be removed. Often the list includes old APK installation packages, remote application files and advertising debris.
For a deeper cleanup, there's a Cleanup section on the menu where you can select specific file categories, and the system will remove temporary files, ad cache, and unused packages, and it's a great way to quickly get a few hundred megabytes of free space without risking damaging important programs.
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Periodically run a deep cleanup in the Security app after installing a large number of new apps or games to delete installer files.
Manually clearing the cache of individual applications through settings
If the memory problem is related to a particular application, for example, Instagram or TikTok take 2-3 GB, they need to be cleaned individually. To do this, go to the Settings menu, then select the App section and click All Apps. In the list that opens, find the "heavy" application and tap it.
In the app information menu, you're interested in the Memory button or the immediately available Clear button (bottom of the screen). When you click Clear, the system will offer two options: Clear cache and Clear everything. Choose the former option to save your accounts and settings, a method that is particularly effective for instant messengers and social networks that aggressively accumulate media cache.
It's worth noting that once cleaned, the application can run a little slower on its first run, as it has to re-download the necessary resources, but this is a one-off phenomenon that will quickly be replaced by performance gains and freeing up real disk space.
☑️ Checklist for manual cleaning
Cleaning through engineering menu and storage
The newer versions of MIUI installed on the Xiaomi 9C have easy access to detailed memory statistics. Go to Settings → About Phone → Storage. Here you will see a color diagram showing what exactly the memory is occupied with: applications, images, videos or system files. By clicking on the category "Applications", you can sort the list by the size of the space occupied.
The good thing about this method is that it visually shows memory eaters, and it often turns out that the gallery is bloated by a basket where deleted photos are stored for another 30 days, and cleaning the cart in the gallery and files is also part of the cache work, because these files are technically deleted by the user, but physically still take up space.
Also in this section you can find hidden system caches, such as the cache of Google Play Services updates or the theme store cache. Be careful with system applications marked with the Android icon: their cache is better not to touch unless urgently necessary, as this can lead to unstable interface operation.
| Type of data | Can I remove it? | Impact on the system | Where to find out. |
|---|---|---|---|
| Cash app. | Yes, it's safe. | Acceleration, clearing space | Settings → Applications |
| Application data | No (no backup) | Reset logins and settings | Settings → Applications |
| Files.thumbnail | Yes. | Gallery acceleration | DCIM folder |
| System cache | Carefully. | Possible reboots | Recovery mode |
Delete temporary files through the conductor
For more advanced users, direct work with the file system is available through standard Explorer. At the root of the internal drive, folders with remote application names or temporary logs often accumulate. Go to the root directory and look for folders with names like MIUI, Android, Tencent (if you use products from this company).
The DCIM folder is often hidden inside the.thumbnails folder, which stores thumbnails of all your photos and videos. Over time, this file can grow to 1-2 GB. It can be safely deleted - the system will create a new one when you open the gallery again, but the place will be freed up instantly. Hidden folders are visible if the Explorer settings include "Show Hidden Files".
Browsers and instant messengers often save documents, pictures and installation files that the user forgets about, and revising this folder once a month is a good habit to keep order on Redmi 9C.
⚠️ Attention: In the folder Android/data You can only delete the contents of folders that you know exactly the names of and that are related to remote programs.
What if the.thumbnails folder is constantly growing?
Using the Developer Mode to Clean
Xiaomi has hidden memory management capabilities available through developer mode, and you need to quickly click on MIUI Version 7 times in the About Phone menu to activate it, and when the notification “You are a developer” appears, a new menu will appear in the expanded settings.
In the For Developers section, look for the Apps section, where you can find the option "Do not remain active" (not recommended for constant operation, since the phone will constantly restart applications) or force processes to stop. A more useful feature is the ability to see running services and stop those that consume resources in the background.
This method is more suitable for diagnosing problems when your phone is hanging because of a hanging process than for cleaning the space, but knowing these tools helps you understand more about how Android manages your smartphone’s resources.
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Developer mode is a powerful diagnostic tool, but for normal cache cleaning it is better to use standard methods so as not to disturb the stability of the system.