How to Clean Cache on Xiaomi 9S: The Complete Guide

Redmi K20 smartphones, known globally as Xiaomi Mi 9T Pro or 9S, are famous for their performance. However, over time, even the most powerful Snapdragon 855 processor can start to run slower. Often the brakes are caused by overcrowded system memory and accumulated digital debris. Cache cleaning is the first and safest procedure to perform to restore performance.

Unlike a full reset, deleting temporary files does not affect your personal photos, contacts or installed applications.This is a routine maintenance task for the MIUI or HyperOS operating system, which you need to do regularly. In this guide, we will discuss all available methods, from standard tools to advanced techniques for experienced users.

Why you need to clean the cache on Android

Cache is a temporary file that applications create to speed up their work, such as the browser saves copies of visited pages, and the navigator saves sections of the map. However, over time, this data becomes obsolete, takes up precious space and may contain errors.

Cleaning them regularly allows you to free up gigabytes of space and fix bugs in the work of programs. If an Instagram or Telegram app is not working correctly, it is cleaning their cache often solves the problem without reinstallation. It is important to understand the difference between cache and application data: deleting data will return the program to the “just installed” state.

⚠️ Warning: Never delete Data in system applications unless you are sure of the consequences.This can cause Wi-Fi settings, alarm clocks and interface personalization to reset.

There is a myth that constant cleaning is bad for the smartphone.In fact, modern versions of Android manage memory effectively themselves, but manual cleaning of heavy applications is still relevant for devices with a small amount of internal memory.

Use of the built-in "Security" application

The easiest and safest way for most users is to use a regular tool from Xiaomi. Security is already pre-installed on the system and has access to all the necessary parts of the file system, it automatically scans the device for excess files.

To get started, find a shield icon on your desktop and run it. Press Speed or Clean to start the scan. The system will analyze the volume of temporary files and suggest deleting them. This is a baseline level that only removes surface debris.

A deeper analysis is done through the Cleanup section inside the application, and here you'll see the details of what exactly takes up space, you can selectively delete the cache of specific programs or the system cache of updates, and you can set up automatic cleanup in the settings of the application itself so that it runs on a schedule.

After the procedure is completed, it is recommended to restart the device, which will allow the system to redistribute resources and permanently delete blocked files that were not deleted during the operation of the OS. This approach is most safe for inexperienced users.

Manually cleaning the cache of individual applications

If a particular program is slow or takes up suspiciously much space, individual cleaning is required. Social networks and instant messengers tend to grow to giant sizes, storing thousands of images and videos viewed, and this is managed through the Android settings menu.

Go to Settings → Apps → All apps. Find the right program in the list, such as YouTube or Chrome. In the menu that opens, select Memory or Storage. There you will see two buttons: Clear cache and Clear everything.

Use the Clear Cache button for quick optimization, but if you want to reset your app settings completely (like logging out and deleting temporary login files), use Clear Everything.

Special attention should be paid to multimedia applications. In the settings of the Telegram itself, there is a section called "Data and memory", where you can set the automatic cache cleanup in 3 days or a week, which will eliminate the need to do this manually in the future.

Cleaning the system cache through Recovery Mode

For deeper cleaning, affecting system temporary update files and application installation, Recovery mode is used.This method does not delete personal files, but cleans the Dalvik Cache partition, which contains optimized application code.

To enter recovery mode, turn off the smartphone completely. Then press the power and volume buttons at the same time. Hold them until the Mi logo appears, then release the power button, but keep the volume. In the menu, the navigation is done with volume buttons, and the choice is made with the power button.

In the menu, select a language (if available) and find Wipe Data. It's important not to confuse the options. You need Wipe Cache (or Clean Cache), not Wipe All Data. The latter will completely destroy all your data, returning the phone to a factory state.

⚠️ Attention: In Recovery mode, the touch screen is not working. Use the volume buttons to move up and down and the on button to confirm the choice.

Once you've selected the cache cleaner, the system will request confirmation. You'll agree and wait for the process to be completed. It usually takes a few seconds. Once you've cleaned it successfully, select Reboot to restart. The first run may take longer than usual, which is normal, since the system will re-optimize the applications.

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If the phone is still slow after cleaning the cache in Recovery, check the free space.To work smoothly, Android needs to keep at least 10-15% of its total storage free.

Cleaning DNS cache and network

Sometimes, problems with Internet speed or page loading are not related to memory, but to the network cache. DNS-requests to open frequently visited sites faster if IP-The address of the site has changed, and the phone remembers the old one, access will be impossible.

For cleaning. DNS-You can use the hidden menu of the engineering tests to access the phone app and type ##4636##. If the code doesn't work (depends on version). MIUI), Go to Settings. → The phone. → Version. MIUI Quickly press 7 times to activate the developer mode.

Then, in the advanced settings, look for General Information (or search for Testing settings). Select Wi-Fi Statistics or Phone Information. You can reset the DNS Menu (if available in your version). A more general way is to turn on and off Flight Mode or reboot the router.

adb shell pm trim-caches 999999999

For advanced users with access to ADB (Android Debug Bridge), there is a command to force the cache to a certain size. The team above cuts the cache of all applications, leaving no more than 1 GB (value in bytes), a powerful tool that requires a connection to a PC.

Automation and third-party utilities

Instead of manually doing things, you can use automation, applications like SD Maid or Files by Google can find files left over from uninstalling programs, and they analyze the file system more deeply than a standard Xiaomi cleaner.

But be careful with so-called accelerators and antiviruses from unknown developers, who often consume a lot of resources and show intrusive advertising, and the best optimization is control over what you install and regular manual inspection of the storage.

Set up automatic cleaning in Xiaomi's Security app. Go to the app's settings, find Auto Waste Cleanup and turn it on. It's also helpful to set up cleaning in messenger apps by limiting the shelf life of media files in the cache.

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Regularly cleaning the cache prolongs the life of the smartphone drive, preventing its wear from constant cycles of overwriting temporary files.

Frequently Asked Questions (FAQ)