Cleaning up storage on Xiaomi Mi 9: a complete guide with step-by-step instructions

Xiaomi Mi 9 is the flagship smartphone of 2019, which still remains relevant thanks to the powerful hardware and regular updates to MIUI. However, even 64/128 GB of internal memory over time get clogged with unnecessary files: app cache, duplicate photos, remnants of remote programs. If your Mi 9 began to slow down, issue notifications about memory shortages or refuse to install updates, it’s time to conduct a general cleaning.

In this article, you will find 7 proven ways to clean storage, from basic (hand-held garbage removal) to radical (factory reset), we will analyze which files can be safely deleted and which should not be touched, and we will give tips on optimizing memory to extend the life of the device. All instructions are adapted for MIUI 12-14 and do not require root rights.

Before you start, check how much space is occupied right now: go to Settings → About Phone → Storage. If less than 10% of the total is free, the smartphone will start to run slower, as Android needs “free” memory for temporary files.

1. Delete cache and unnecessary files through MIUI settings

The easiest way to free up 1-3 GB of memory is to clear the cache of applications and system debris. Cache speeds up programs, but over time grows to giant sizes (especially for instant messengers, social networks and games). MIUI There is a built-in tool for this task:

1. Open the Settings → Storage.
2. Slip on "Clean" in the "Junk Files" section.
3. Select Categories to Remove: 🗑️ Application cache – temporary data (safe to delete). 📁 Download files – Download folder (check if there is any important file!). 🎵 Music and video – multimedia cache (e.g. preview for gallery). 📱 APK-Files – Remains from installed applications.

"Clean it up."

⚠️ Note: Do not delete files in the System Data section manually – this can cause malfunctions MIUI. To clean them, use only built-in tools or specialized utilities (we will talk about them below).

Application cache (does not affect account data)

APK-Files (Installation Packages of Already Installed Programs)

Empty folders in the "Downloads" section

Previews and miniatures of multimedia-->

After cleaning, restart your smartphone, which will help the system recalculate the space and apply changes. If less than 500 MB is free after the procedure, move to the next method.

2. Clean Memory with Security App

The Security app in MIUI is not only an antivirus, but also a powerful memory optimization tool, which can find duplicate photos, large files, unused applications, and even analyze which programs eat the most space.

How to use:

1. Run the Security app (if it isn’t on your desktop, search through search).
2. Go to the “Cleaner” tab.
3. Click on “Deep Clean” and wait for analysis (may take 1-2 minutes).
4. Examine the results: 🔍 Unnecessary files – cache, logs, temporary data. 📸 Duplicate photos – same photos (check manually!). 🎮 Large files – videos, games, archives (>100MB). 📦 Unused applications – programs that are not used >30 days.

"Clean it up."

Important: Large Files often include backups (.bak), archives with chats (.zip from Telegram) and videos from stories. Before deleting, open the MIUI/Backup or Download folder and manually check the contents.

💡

If the Security app doesn’t find duplicate photos, try third-party utilities like Files by Google or CCleaner – they often do better than built-in tools.

3. Manually delete unnecessary files through the Explorer

The File Manager built into MIUI allows you to manually browse folders and delete files that are not visible through standard settings, which is useful if you want to control the process or are looking for specific data (such as old backups).

Key folders that are worth checking out:

To open hidden folders (for example, with a messenger cache), tap three dots in the upper right corner of the Explorer → Settings → turn on “Show hidden files”.

⚠️ Warning: Never manually delete files from folders: /system, /vendor, /data/data (If you don't have root rights, you won't see them anyway, but if you do, you'll be warned, and that could lead to a system crash and you need to flash it again.

4. Clearing the cache of individual applications

Some programs (especially social networks and instant messengers) accumulate a giant cache that is not always deleted through a standard cleanup, for example, Telegram can take 5+ GB only from downloaded stickers and media, and Facebook can store video cache in the background.

How to clean the cache of a particular application:

1. Open Settings → Applications → Application Management.
2. Select a program (such as Instagram or VK).
3. Put it on the Vault.
4. Click Clear Cache (not to be confused with Clear Data – this will delete all settings and accounts!).
5. Check the obb folder: Go to /storage/emulated/0/Android/obb. Delete files with the names of remote games (e.g. com.pubg.krmobile).

⚠️ Note: Some system applications (such as Mi Video or Mi Music) cannot be removed by standard means. ADB-We don't recommend doing this without experience -- risk disrupting the work. MIUI too high.

If you install and delete games/programs frequently, install SD Maid (from Google Play) which can find and remove junk folders from long-distant applications.

💡

Delete apps via Settings → Apps don’t always clean all their files. Always check /Android/data and /Android/obb folders manually!

6. Transfer files to a memory card or cloud

If the internal memory is catastrophically lacking, and you do not want to delete data - transfer some files to microSD or cloud storage. Xiaomi Mi 9 supports memory cards up to 256 GB (in a hybrid slot, instead of a second SIM).

How to transfer files to microSD:

1. Insert the memory card (if you haven’t already done so).
2. Open Explorer and select files to transfer (photo, video, music).
3. Slip on three dots in the upper right corner → “Select” → tag files.
4. Click on the Move (or Copy) icon and select the memory card (/storage/XXXX-XXXX).
5. Restore Data: After restarting, follow the instructions of the setup wizard. Restore backup from Settings → Additional → Restore.

Critical: If you forget the Mi-account password, a factory reset can lock your phone (activate Mi Cloud Lock).Be sure to log out of your Xiaomi account before resetting to Settings → Accounts → Mi Accounts →

Once reset, the smartphone will be like new, with free memory and standard settings. Install only the necessary applications and regularly clean the cache to avoid refilling the storage.

FAQ: Frequent questions about memory cleaning on Xiaomi Mi 9