Smartphone Xiaomi Redmi Note 9 is a popular device that has been faithfully serving millions of users for several years. However, over time, even the fastest device begins to work slower, and notifications about lack of space appear more and more often. This is a natural process of accumulation of temporary files, application cache and media content, which inevitably clogs up the internal storage. Owners Android smartphones often encounter the fact that the system begins to “slow down” precisely because the memory section is full.
In this article we will analyze in detail all the available ways to optimize storage specifically for your model. We will not use third-party “cleaners”, which often consume resources themselves, but will focus on built-in shell tools MIUI and proven manual cleaning methods. You'll learn how to safely delete unnecessary data without losing important contacts or photos. The right approach will allow you to return the device to its former speed without the need to reset to factory settings.
The main reason for lack of space lies not only in installed games, but also in hidden system processes. Messengers like WhatsApp i Telegram have the ability to quietly accumulate gigabytes of data over months of use. Before deleting something important, you need to diagnose and understand what exactly is taking up precious gigabytes on your drive. Let's move on to practical steps.
Analyzing storage capacity through system settings
The first step should always be diagnostics. The shell MIUI has an excellent built-in tool that clearly shows the distribution of space. You don't need to install third-party apps to analyze your disk. Just go to the menu Settings → Memoryto see the color diagram. Here the system automatically categorizes files by type: applications, images, videos, documents, etc.
Pay special attention to the “Other” section. Often this is where remnants of uninstalled apps or temporary update files are hidden that the system cannot classify. If this partition takes up a disproportionate amount of space (for example, more than 10 GB on a model with 64 GB of memory), this is a signal for a deeper cleaning. By clicking on any colored sector of the diagram, you will be taken to a detailed list of files, where you can immediately mark unnecessary ones for deletion.
Sometimes the system offers automatic garbage cleaning directly in this menu. The Clear button is usually located in the lower corner of the screen. It will safely remove application cache and advertising files that do not affect the operation of apps. However, you should not rely only on the automatic mode, as it often skips heavy files in download folders.
⚠️ Attention: Before mass cleaning the "Other" section manually, make sure that there are no important backup copies of chats or work documents that you have not transferred to the cloud.
Regularly check the memory chart once every two weeks to prevent critical storage from being filled to more than 90%.
Using the Security application and clearing the cache
Each smartphone Xiaomi has a pre-installed system application "Security" (Security). This is a basic device maintenance tool that combines an antivirus and a memory cleaner. Launch it and select Cleanup. The scanner will analyze the device and offer to remove “Garbage”. Typically these are cache files, image thumbnails and remnants of installation packages APK.
After quick cleaning, click on the button Deep cleaning. The functionality here is much wider. You'll be able to find large files that you forgot to delete, such as old travel videos or downloaded movies. There is also an "Applications" section, which shows the cache size for each installed app. This allows you to specifically clear the data of heavy applications, such as Instagram or YouTube, without deleting them completely.
When clearing the messenger cache, be careful. The Security application often has a separate section for WeChat, WhatsApp and Telegram. The system will offer to delete the cache, but will leave important media files. However, it is always better to double-check whether the necessary photos have been deleted from the correspondence before confirming the action.
- 🗑️ Delete the cache of applications that you have not used for more than a month.
- 📸 Check the “Recently Deleted” folder in the gallery - files there take up space for another 30 days.
- 📦 Sort files by size in the “Large Files” section to find hidden large archives.
Manual cleaning of the Downloads and Duplicates folder
Folder Download (Downloads) is a “black hole” in the memory of most users. By default, browsers and instant messengers save all open documents, pictures and installation files there. Over time, hundreds of megabytes of unnecessary junk accumulate there. Go to the application Conductor and open this directory. Feel free to delete old installers - after installing the app, they are no longer needed. On APK files installers - after installing the app, they are no longer needed.
Duplicate photographs deserve special attention. On Redmi Note 9 with a high-resolution camera, one photo can weigh 5-10 MB. If you often take a series of pictures or save pictures from the Internet, you probably have copies. The Gallery application sometimes has a built-in search function for similar images, but it is safer to use a file manager to manually view folders. Also check the messenger folders inside the internal memory. For example, on the way DCIM And Pictures.
Also check the messenger folders inside the internal memory. For example, on the way Android/media/com.whatsapp/WhatsApp/Media all received videos and documents are stored. Often there are viral mailings or postcards that you looked at once and forgot. Deleting such folders can free up to 2-3 GB of space instantly.
⚠️ Attention: The file system interface in Android 11 and higher limits direct access to the folder Android/data. To work with it, you may need to provide special permissions to the explorer.
☑️ Check the Downloads folder
Optimization of messengers: WhatsApp and Telegram
Messengers are the main consumers of memory on a modern smartphone. The Telegram implemented an excellent function of automatically clearing the cache, which many ignore. Go to Settings → Data and memory → Memory usage. Set the Keep Media slider to 3 days or 1 week. This will allow the application to automatically delete downloaded photos and videos if you have not opened them for a long time, while they will remain on the server and will be downloaded again if necessary.
In WhatsApp the situation is more complicated, since all files are stored locally. Go to chat settings and select Data storage. Here you will see a list of chats sorted by space. Often the heaviest chats are work groups or family conversations where videos are constantly being sent. You can go to a specific chat, click on the contact's name and select Media, links and documentsto bulk delete old files.
Disable autosaving of media to the gallery for both applications. This will prevent duplication of files: they will be stored inside the messenger, but will not be copied to the general phone gallery, taking up double space. This setting is located in the section Chat in the settings of each application.
| Application | Where to look for settings | What to clear | Security deletion |
|---|---|---|---|
| Telegram | Data and memory | Cache | Completely secure, files in the cloud |
| Data storage | Videos and Documents | Irreversible, a backup is needed | |
| Viber | Device memory | Media | Deletes files from chats |
| Phone settings | Application cache | Safe, does not delete account |
Telegram secret
Unlike WhatsApp, Telegram stores the entire correspondence history on its servers. You can safely clear the entire cache down to 0 bytes, and when scrolling through old correspondence, messages and photos will be downloaded from the Internet again.
Deleting unused applications and games
Games and social networks take up not only space for the installation file, but also create huge amounts of additional data. One game can weigh 100 MB when downloaded, but after downloading resources and cache it will take up 3-4 GB. Go to Settings → Applications → All applications and sort the list by size. This will immediately show the main memory “eaters” on your Redmi Note 9.
Pay attention to pre-installed applications that you do not use. B MIUI some of them can be deleted, and some can only be disabled. Disabling will hide the application from the menu and stop its background activity, which will also free up some system resources. If you see apps like Facebook or LinkedInthat you have not used for months, ruthlessly delete them.
Do not forget about the games that you no longer play. We often leave them “just in case,” but they take up space in vain. If you decide to install the game again in the future, progress can often be restored through your account Google Play or developer profile, so the risk is minimal.
- 🎮 Delete games you haven't played in more than 2 weeks.
- 🛍️ Check for food delivery or taxi apps you haven't used six months.
- 📱 Disable Google system applications if they are not in use (with caution).
⚠️ Attention: Do not remove system components marked “System process” or “Android”, even if they seem unnecessary to you. This can lead to unstable operation of the phone or endless rebooting.
Sorting applications by size in the settings is the fastest way to find hidden sources of memory consumption that are not visible on the main screen.
Transfer data to a memory card and to the cloud
Model Redmi Note 9 supports installation of memory cards of format microSD. This is the most effective solution for long-term storage of photos and videos. You can transfer your entire media library to the card, leaving the internal memory free for the system and applications. Insert the card, go to Explorer, select the files and select “Move” → SD card.
It is also worth considering the option of using cloud storage. Services like Google Photos allow you to set up automatic uploading of pictures to the cloud and then deleting them from the phone’s memory. The Free Up Space feature in the Google Photos app will find all the photos that are already stored in the cloud and delete their local copies. This frees up gigabytes of space without the risk of data loss.
Setting the default save path is also important. Go to the Camera settings and select save to SD card. Then all new pictures and videos will be immediately written to external media, without taking up internal space. A similar setting can be made in the voice recorder and some file managers.
Use memory cards of UHS-I U3 class or higher to record video in 4K, otherwise there may be delays when shooting on Redmi Note 9.
Is it possible to transfer the applications themselves to the memory card on Xiaomi?
In modern versions of Android and the MIUI shell, the ability to transfer applications to an SD card is limited or completely absent for most apps. It's up to application developers to decide whether to allow porting. System applications and important Google services cannot be transferred. However, some files inside applications (for example, the map cache in a navigator) can be configured to be saved to a card through the settings of the application itself.
Why is memory not completely freed after clearing?
Part of the space is occupied by the system partition and swap files that are not visible to the user. Also, if you deleted files but didn't empty the Trash in Gallery or Explorer, the space won't be freed up immediately. Files continue to be stored in the Recycle Bin for 30 days. To free up space right away, you need to go to the trash can and forcefully empty it.
Does full memory affect Internet speed?
There is no direct effect on connection speed, but there is an indirect effect. When memory is critically full (less than 500 MB free), the system cannot effectively cache web pages and application data. This leads to the fact that the browser and apps have to constantly download data again, which creates a feeling of slow network operation and freezing of the interface.
Is it safe to use applications like Clean Master?
Using third-party aggressive “cleaners” on Xiaomi smartphones is not recommended. The built-in MIUI system already has optimized cleaning algorithms. Third-party applications often run in the background, display ads, and may mistakenly delete important system files or the cache that is needed to load apps quickly, which will ultimately only slow down the phone.
What to do if the memory fills up on its own immediately after cleaning?
If the memory fills up instantly, check if USB debugging is enabled with constant logging, or if there is a faulty application running, which creates cyclic error logs. Also check your synchronization settings - your phone may be trying to download a huge library from the cloud. As a last resort, you will need to reset to factory settings with preliminary saving of data.