Cache Clearing on Xiaomi 9T: A Complete Guide for Redmi K20 Users

Xiaomi 9T (also known as Redmi K20 in some regions) is a popular smartphone with powerful hardware, but even it eventually begins to “slow down.” The main reason is clogged: temporary application files, update remnants and system debris take up precious space and slow down. In this article, we will discuss how to properly clean the cache on Xiaomi 9T without deleting important data, and what tools to use to do this.

There are three types of cache: app cache (which speeds up their launch but grows over time), system cache (update and log residues), and Dalvik cache (which optimizes the Android virtual machine), each requiring different approaches, from manual actions to hidden menus, and we'll look at all methods, including those that are not obvious to the average user.

Important: Before cleaning the cache, check the memory space (Settings → About Phone → Memory). If the Other Files are larger than 5-10 GB, it's a good sign that it's time to act. But remember, cleaning the Dalvik cache through TWRP will reset the application optimization, and the first run after it can take up to 5-10 minutes.

1. Clearing the cache of individual applications

The safest way is to remove the cache for specific programs, which won’t affect their data (like saved games or chats), but will free up space. On the Xiaomi 9T with the MIUI shell, there are two ways to do this:

The first is through Settings → Applications → App management. Select the app you want (like Facebook or Google Chrome), tap it and click Clear Cache. The second way is quicker: press the app icon on your desktop, select App Information, and then find the Cleanup button.

• 📱 Social media: VK, Instagram, TikTok – their cache can weigh up to 1-2 GB.
• 🎮 Games: PUBG Mobile, Genshin Impact – Texture and update cache often exceeds 500MB.
• 🌐 Browsers: Chrome, Mi Browser – store copies of pages, history and cookies.
• 📷 Gallery and camera: thumbnails and temporary files can take up hundreds of megabytes.

Tip: If the app gets slower after cleaning the cache, restart the phone. MIUI sometimes doesn't immediately reassemble the optimized data.

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Before clearing the messenger cache (WhatsApp, Telegram), save important media files – they can disappear from chats if they were downloaded as “cached”.

2. Automatic cleaning through "Safety"

MIUI has a built-in garbage cleanup tool called the Security app, which analyzes the system and suggests that you delete unnecessary files, including the cache, and that you can use it to:

1. Open the Security app.
2. Go to the "Cleaning" tab (broom icon).
3. Click on “Scan” and wait for the analysis to be completed.
4. Select categories to clean (we recommend that you note “App Cache” and “Residual Files”).
5. Slip "Clean" and confirm the action.

The advantage of this method is that it removes not only the cache, but also temporary update files, system logs and empty folders. However, be careful: sometimes Security suggests removing files that you may need (for example, downloads from your browser).

Application cache |Residual files after uninstallation |System Logs |Temporary update files |Empty folders-->

If your phone still brakes after cleaning, try turning off the Smart Clean feature in the Security settings, which sometimes aggressively closes the background processes, leading to delays in switching between applications.

3. Manual removal of system cache via Recovery

System cache (/cache) Stores update data, kernels and temporary files MIUI. Cleaning it helps if the phone is slower after the upgrade or overheats frequently:

1. Turn off the Xiaomi 9T.
2. Press the Power + Volume buttons up until the Mi logo appears.
3. From the Recovery menu, select the language (if required), then go to Wipe & Reset → Wipe Cache.
4. Confirm the action and wait for the completion.
5. Reboot your phone (Reboot → System)

This method doesn’t delete user data, but it will reset the settings of some system applications (like Google Play Services). Once rebooted, the first launch of the phone can take up to 2-3 minutes – that’s normal.

⚠️ Warning: Don't confuse Wipe Cache with Wipe Dalvik Cache or Wipe Data.The latter two options will result in a phone reset or the removal of optimized app data.

4. Cleaning Dalvik cache (for power users only)

Dalvik cache is optimized files that speed up application launches. Cleaning it up is useful if you install/remove programs frequently or after manual firmware updates. However, it requires custom Recovery (like TWRP), as the standard Recovery menu on Xiaomi 9T does not provide such an option.

Instructions for TWRP:

1. Load to TWRP (clip Power + Volume up).


2. Go to the "Advanced" section.




3. Select "Wipe Dalvik Cache."




4. Confirm the swipe.




5. Reboot the phone.

After this procedure, each application will be running for the first time (up to 30 seconds) as the system re-optimizes them for your device.

If you are not sure about your actions, it is better not to touch the Dalvik cache. Cleaning it gives an increase in performance only in specific cases (for example, after changing the firmware).

5.Use of third-party cleaning applications

If the built-in MIUI tools don't work, you can use third-party utilities.

• 🧹 SD Maid – Deep Cleanup, including residual files and duplicates.
• 🔍 CCleaner is a simple interface, but less effective for MIUI.
• 📦 Files by Google – Shows large files and unnecessary cache.
• 🛠️ 1Tap Cleaner – Quick cleaning of the cache on schedule.

When choosing a third-party application, pay attention to reviews and permissions. Some utilities (especially from unknown sources) can collect data or show annoying ads. We recommend SD Maid, which is paid, but has a trial period and does not contain malicious code.

⚠️ Warning: Don't use apps that promise to "speed up your phone 300%" or "free up 10GB in 1 click" most often it's a hoax, and some install malware. Check the developer and read reviews before installing.

Tip: After cleaning the cache with a third-party app, restart the phone, which will help MIUI recalculate the free space and avoid memory glitches.

6.When cleaning the cache doesn't help: alternative solutions

If Xiaomi 9T continues to slow down after all the manipulations, the problem may be deeper:

• 🔋 Worn-out battery: at health levels below 80%, the phone begins to limit performance.Check battery status through Settings → Battery. → Battery status.
• 🔄 Outdated firmware: MIUI 12 and newer are better optimized than older versions.Update via Settings → The phone. → Updating the system.
• 📱 Overheating: if the processor overheats, it lowers the frequencies.Clean the phone of dust and avoid use in the heat.
• 🧩 Background processes: Some applications (especially Chinese) run hidden services. → Permits → Auto-start.

If nothing works, consider resetting to factory settings. Before doing so, be sure to back up through Settings → Additional → Backup and Reset or Mi Cloud. Reset will delete all data but return the phone to factory speed.

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Cache cleaning is a temporary solution, and if the phone is slowing down because of weak iron or a worn-out battery, it will only help to replace components or buy a new device.

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