Redmi series smartphones have long proven to be reliable devices with excellent value for money, but even powerful processors can be over time lacking resources. Cleaning up memory on Xiaomi Redmi 9 becomes an urgent task when the system starts to run slower, applications open longer, and notifications of space shortages appear more often. Users often face a situation where 64 or 128 gigabytes of internal storage suddenly become full for no apparent reason.
In the Android-based MIUI operating system, temporary files are stored in the background all the time, which is a normal process for modern applications that cache data for faster access, but over time, this cache turns into digital garbage. Proper management of internal storage allows you not only to free up gigabytes of space, but also to extend the life of the drive, and stabilize the interface.
In this guide, we will take a look at all the optimization techniques available, from built-in tools to manual settings that will help you get your device back on track. You will learn which folders you can remove safely, how to set up automatic cleaning correctly, and why standard methods are not always 100% effective.
Analysis of storage occupancy and search for large files
Before taking action to remove data, you need to make a thorough diagnosis of what exactly occupies space. The standard “delete everything” approach often leads to the loss of important documents or photos, so the first step is to visualize the occupied space. Redmi 9 owners can use the built-in analyzer that shows the distribution of memory into categories: applications, images, videos, documents and system files.
The most voluminous elements are usually messengers like WhatsApp or Telegram, which store the received media files for years, and the cache of streaming services and browsers, as well as system logs of updates, and understanding the structure of files helps make an informed decision about what can be deleted without compromising the functionality of the device.
⚠️ Note: Before mass deletion of files from system folders, it is strongly recommended to back up important data in the cloud or on your computer, as it may be impossible to restore the remote system log.
For detailed analysis, you can use the built-in Security app, which provides a fairly accurate picture of the disk filling. However, for a deeper dive, it is worth considering third-party solutions, although in most cases, Xiaomi’s standard tools are enough for an initial assessment of the situation.
Special attention should be paid to the Download folder, where installation files of applications (APKs) that have been installed for a long time and are no longer needed are often downloaded, and deleting them is the safest way to quickly free up several gigabytes.
Use of the built-in MIUI cleaning tool
Each Xiaomi smartphone has a Security system app preinstalled, which includes quick optimization functionality. This is the first tool worth turning to, as it has access to system partitions closed to third-party programs. Launching the Cleanup feature allows you to delete temporary files, remnants of remote applications and advertising debris accumulated by the system.
The process takes only a few minutes and requires minimal user involvement. Once scanned, the system will suggest removing files it considers safe to delete. It is important to understand that this method is effective for regular maintenance, but will not solve the problem radically if the storage is clogged with personal files of the user.
☑️ Daily optimization
For a deeper look inside the Security app, there's a Storage section, where you can analyze the content in detail and find duplicate photos or large files you forgot to delete. MIUI algorithms are smart enough not to touch systemically important files, but manually checking results before confirming deletion is never superfluous.
It is worth noting that regular use of built-in cleaning helps keep the system on top, preventing critical disk filling that can lead to cyclical reboots. However, if the site runs out again quickly after cleaning, the problem lies deeper - most likely in a particular application or process.
Working with the cache of applications and messengers
The main “eater” of free memory in modern smartphones are social networks and instant messengers. Apps like VK, Instagram, Telegram and WhatsApp store every picture, video and voice message viewed in a local cache. Over time, this cache can reach tens of gigabytes, which is critical for models with 64 GB of internal memory, such as the basic version of Redmi 9.
Cleaning the cache through your system settings is the safest method that doesn't affect your personal correspondence and accounts, so you have to go to the settings menu, find the Apps section, and select the specific application. Inside the app menu, select Memory and click Clear Cache. It's important not to confuse this button with Clear All, because it will delete the account login and all local data.
| Annex | Type of data | Safety of cleaning | Recommended frequency |
|---|---|---|---|
| Telegram | Media cash | High (data in the cloud) | Once a month |
| Photo/Video | Medium (needs backup) | Once in 3 months | |
| YouTube | Temporary files | Tall. | Once a week. |
| Chrome | Cash sites. | Tall. | Once a month |
Some messengers, like Telegram, have an automatic cache cleaning feature built in, so by going to the app settings, the Data and Memory section, you can set a cache size limit or a period after which old files will be deleted automatically, and this is the most effective way to combat the proliferation of garbage for active messenger users, allowing you to forget about manual cleaning forever.
What happens if you clear the application data?
And don’t ignore the cache of Google’s system services, which sometimes grows to unimaginable sizes due to synchronization or errors in the operation of the Play Market services, and cleaning it often solves problems with the interface freeze.
Removing duplicates and unnecessary media files
Over the years of smartphone use, the gallery has accumulated a huge amount of screenshots, failed photos, repetitive videos and chat memas. These files not only take up space, but also make it difficult to find the really important points. MIUI has a built-in tool to find duplicates, but often it misses similar but technically different files.
For good cleaning, manually walk through Screenshots and Downloads, often containing images of checks, tickets or temporary information that has become obsolete, and removing video files has the greatest effect, as one minute of high-resolution recording can take up more space than a thousand text documents.
⚠️ Note: Be careful when removing files from.thumbnails or system album folders if you are not sure about their contents.
Using cloud services such as Google Photos or Yandex.Disk, you can free up space on your device by moving the originals to the cloud. The “Free up space” feature in Google Photos automatically removes from the device those pictures that have already been successfully uploaded and saved in the cloud account.
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Turn on the “Smart Cleanup” function in the settings of the Xiaomi Gallery – it automatically suggests removing blurred photos and similar pictures taken in the serial shooting mode.
It's also worth checking the DCIM/.thumbnails folder, which is a hidden system folder that stores thumbnails for quick display of the gallery, sometimes up to several gigabytes in size, and you can clean it up through the file manager by enabling hidden file displays, but remember that after that, the gallery will take longer to download the previews the next time you run.
Managing installed applications and games
Often, we install apps just in case, or use them only once, forgetting to delete them, and each application takes up not only space for the installation file itself, but also creates additional data, cache and libraries. With Redmi 9’s limited memory, having a dozen unused programs can be critical.
Do a software audit. Go to your settings and sort apps by size or date of last use. If you haven't opened a game or utility in the last six months, chances are you don't need it. Removing heavy games like PUBG or Genshin Impact can free up 5-10GB of space instantly.
For applications that you rarely use but don’t want to delete (like a bank or airline app), you can use the Freeze feature or simply limit their background activity, which will prevent them from accumulating cache during downtime.
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Regularly auditing installed applications is the best way to prevent memory loss, removing what you don't use immediately without delaying it.
Also worth paying attention to are pre-installed apps (bloatware) that come with firmware, many of which can be removed or at least disabled so that they do not update or take up space. Be careful: removing system components can lead to unstable phone operation.
Use of memory card and cloud storage
One of the features of the Xiaomi Redmi 9 is the availability of a slot for a microSD card. This is a great solution for those who store a lot of photos, videos and music. By transferring media files to an external drive, you can significantly relieve internal memory, leaving it for the system and applications.
To use the memory card as part of internal storage (although this feature is limited in newer versions of Android), you can format it as internal memory. However, a more reliable option is simply to set the camera and messengers to save files by default on the device. SD-This is done in the settings of each particular application.
Cloud storage also plays a major role, because if you have a Google One subscription or similar service, you can store document archives and old projects there, leaving only current files on your phone, which makes your smartphone a data terminal, not a data warehouse.