Modern smartphones like the Xiaomi Redmi 9 have impressive specs for their price segment, but even 64 or 128 gigabytes of internal memory fill up over time. Users often face a situation where the device starts to run slower, and notifications of a lack of free space appear at the most inopportune moment, this is due to the accumulation of temporary data, remnants of remote applications and the cache of instant messengers.
The MIUI system that makes up Redmi’s shell has built-in protection and optimization mechanisms, but they don’t always deal with deep debris that you wouldn’t see in a gallery or conductor. To get the gadget back to its former sharpness and free up precious gigabytes, you need to do a comprehensive clean that affects not only obvious folders, but also hidden system partitions.
In this guide, we will discuss effective ways to delete unnecessary files without risking losing important contacts or photos. Android/data, which directories can be removed without consequences and whether it is worth using third-party utilities to deep clean the system of your smartphone.
Analysis of memory occupancy in MIUI
Before you start taking any radical action, you need to understand what exactly occupies space on your Redmi 9. The built-in storage analyzer provides detailed information about the distribution of data, but many users ignore this tool, relying only on general feelings about the lack of space. Competent analysis allows you to identify memory eaters, which are often not applications, but their cache.
For detailed statistics, go to Settings → About Phone → Memory. This is where the system will suggest a standard cleanup, but we're interested in a deeper analysis. By clicking on the Clean button, you'll be taken to the standard Security app menu, where you can see a breakdown by category: images, videos, documents and, most importantly, "Other."
- 📱 Applications: Often take up more space due to the cache than the installation folder itself.
- 📷 Multimedia: high-resolution photos and videos quickly eat gigabytes.
- 🗑️ Recycle Bin: Deleted files can be stored for up to 30 days, taking up space.
- 📦 Downloads: Forgotten installation files APK and browser documents.
Special attention should be paid to the category “Other”, which in MIUI often inflates to obscene size, including temporary update files, error logs and offline map data, and understanding the structure of the storage is the first step to successfully optimize the device without losing the necessary information.
Use of the built-in "Security" application
Xiaomi’s standard Security app is the first tool to use, and it can find obvious garbage, duplicate photos, and remnants of deleted programs, but to get the most out of it, you need to use its advanced features rather than just a “Scan” button.
Start the app and select "Clean up." After the initial scan, don't rush to delete everything in a row. Scroll down to the "Deep Cleanup" section. That's where big files are hidden that you may not even remember: old WhatsApp videos, game installer packages, and unnecessary archives.
☑️ Checking before cleaning
In the Big Files section, you can often find forgotten movies or archives that were downloaded months ago, sort them by size, which allows you to quickly free up a significant amount of memory by removing just a couple of objects. Be careful: delete only the one that you are 100% sure of.
⚠️ Note: Cache Clearance in the Security app may delete authorization data in some applications.Be prepared to re-enter passwords on social networks or online banks after the procedure.
Also available on this menu is the "Unused Apps" cleanup function, which will analyze the statistics of how programs are launched and suggest removing those you haven't used in a long time, which is a great way to get rid of the software that only slows down Redmi 9.
Manual cleaning through File Explorer
Automatic cleaners don’t always see specific debris left by browsers or document editors, which requires manual access to the file system through a standard File Manager, and it’s important to be careful, as deleting system files can lead to unstable operating systems.
First of all, check the Download folder. Often this is where files that used to take one minute accumulate and now just take up space, and it's worth checking out the Bluetooth folder if you've ever taken files on this protocol - old photos and music can lie there for years.
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Use date-based file sorting in Explorer to quickly find and delete old bulky files that were forgotten a few months ago.
Of particular interest to Xiaomi owners is the MIUI/Gallery/cloud/cache folder, which stores thumbnails and cache of the cloud gallery. If you don't use Xiaomi's cloud sync, the contents of this directory can be safely deleted - this will free up hundreds of megabytes.
Another important directory is Tencent/MicroMsg, which stores WeChat data and, in some cases, WhatsApp data residues. Inside a folder with a long character set (this is your account ID), you can find a Video or Image subfolder, where all media files ever received are stored, and cleaning them through a conductor is often more effective than through the settings of the messenger itself.
Working with Android: Data and OBB folders
Since Android 11 and up, access to the Android/data and Android/obb folder has been restricted for security reasons, but Redmi 9 with current MIUI firmware still has access to them, which is critical for deep cleaning, and it's where game cache, offline navigator maps and streaming service data are stored.
The OBB folder contains the heavy app data: game graphics, sound packets, maps for navigation. If you delete a game but the folder with its name is still there, you can erase it. But with the Data folder, you need to be extremely careful: deleting files inside can reset the progress of games or application settings.
How to access Android/data on new versions of Android?
Often, after you delete heavy games like PUBG or Call of Duty, gigabyte files remain in the obb folder. manually deleting them is the fastest way to get back to space. Find folders with packet names (like com.tencent.ig) and check their contents.
For navigation applications like Yandex Navigator or Google Maps, this directory stores maps of regions, and if you rarely use offline mode, removing downloaded maps through the app’s settings or manually in the data folder will free up a significant amount of storage.
Cleaning the cache of messengers and browsers
Messengers are the main culprits behind memory overflows on modern smartphones. Telegram, WhatsApp and Viber store every photo and video viewed in the device's memory, creating giant archives. Standard system cleaning often does not touch this data deeply.
Telegram is better cleaned through the settings of the application itself: Settings → Data and memory → Memory Use → Clear cache. Here you can set up autodelete media files so that the cache does not grow in the future. This is a safe procedure, since all media remain on the server and will be re-downloaded if necessary.
With WhatsApp, the situation is more complicated: media files deleted in chat often remain in the WhatsApp/Media/.Statuses folder or in the gallery’s shared folders. It is recommended to use the built-in storage management function inside WhatsApp (Settings → Data and Storage → Storage Management) to see the heaviest chats and clean them selectively.
⚠️ Attention: When clearing browser data through application settings (Applications) → All applications → Chrome → Warehouse → You will lose your saved passwords and history if you do not sync them with your Google account.
Browsers also accumulate gigabytes of temporary files. Go to your browser settings and find History or Privacy. Clearing up the cache of images and site files often frees up 200-500 MB, which can be palpable for a budget Redmi 9.
Comparison of cleaning methods and their effectiveness
Different cleaning methods have different levels of system impact and different levels of security, so that you can choose the best option for your situation, we have prepared a comparative method table.
| Cleaning method | Efficiency | Security | Difficulty |
|---|---|---|---|
| Annex "Security" | Medium | Tall. | Low. |
| Hand-cleaning folders | Tall. | Medium | Medium |
| Reset to factory settings | Maximum | Low (Data Loss Risk) | Tall. |
| Third-party utilities (Clean Master) | Low/Mediocre | Low (advertising, data collection) | Low. |
As you can see from the table, the middle ground is the combination of built-in MIUI tools and careful manual cleaning of media folders and downloads. Using third-party accelerators often does more harm than good, as they consume resources and display ads.
The radical method, Hard Reset, is 100% effective, but takes time to reset and transfer data, and only use it if the phone is critically slow and software cleaning is not working.
Prevention and automation of service
To avoid reverting to cleaning every two weeks, you should set up automatic maintenance. MIUI has an Advanced Cleanup feature that can be set to automatically start when you lock the screen or reach a certain occupancy threshold.
It is recommended that you regularly check the folder "Recently deleted" in the Gallery, the files are stored there for 30 days, continuing to take up space, and also turn off the auto-save statuses of WhatsApp, if you do not plan to save them - this will eliminate the need to clean hidden folders.
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Regular manual check of the Download folder once a month prevents the accumulation of gigabytes of unnecessary garbage more effectively than any automatic programs.
Use Google Photos (Yandex.Disk) with space-free function, which automatically removes photos from the device that are already uploaded to the cloud, leaving only thumbnails available, ideal for owners of models with limited internal memory.