Xiaomi Mi 9 Memory Cleanup: A Complete Guide to Freeing Up Place

Xiaomi Mi 9 is the flagship smartphone of 2019, which still remains relevant thanks to the powerful hardware: Snapdragon 855 processor, 6/8 GB of RAM and 64/128 GB of internal storage. However, even these characteristics do not save from the problem of crowded memory. Over time, the device begins to “brake”, the applications fly out, and the system gives a notification “Memory is full.” In this article, we will discuss 7 effective cleaning methods, including hidden MIUI functions, which will help return the Mi 9 to factory performance.

The main challenge is to correctly identify junk, and many users mistakenly delete useful system files or cache of important applications, leading to crashes, showing what can be removed without risk and what is best left, and looking at alternative methods for those who do not want to waste time manually cleaning, from built-in MIUI tools to third-party utilities with proven security.

1. Analysis of occupied space: what exactly is the memory?

Before you start cleaning, you need to understand which files and applications are eating up the lion's share of memory. The Mi 9 has a built-in tool for this - Settings → Phone → Memory. Here you can see a diagram of the space distribution by category: System Data, Applications, Media Files, Cache and Other.

Pay special attention to the Others section, which often hides temporary files, deleted app residues and duplicates. If this partition takes up more than 10 GB, this is a direct signal to deep clean. Also check the Media category: HEIF photos (used by default in Mi 9) can weigh 2 times less than JPEG, but still take up up to 50% of the memory due to automatic backup in Google Photos.

• 📊 System data – usually 5-8 GB (do not touch unless absolutely necessary!).
• 📱 Apps – Check out games (Genshin Impact can weigh 15, for example)+ GB).
• 🖼️ Media files - video in 4K, RAW-Photos, uploaded memes from messengers.
• 🗑️ Cache – temporary application files (you can clean safely).
• ❓ Other - the most insidious section: there may be error logs, system dumps, remnants of updates.

⚠️ Note: If the System Data section is more than 12 GB occupied, this may indicate file system damage, in which case only a factory reset or a Fastboot flashing will help.

2.Cleaning the app cache: safe and fast

Cache is a temporary file that applications create to speed up work. Over time, they accumulate and can take up to 3-5 GB. In Mi 9 there are two ways to clean the cache: selective (for individual applications) and global (for all at once).

For selective cleaning:

1. Go to Settings → Applications → Application Management.
2. Select an app (such as YouTube or Telegram).
3. Click Clear Cache (not to be confused with Clear Data – this will delete all settings!).

For global cleaning:

1. Open Settings → Memory → Cleaning.
2. Click “Clear the cache” (the system will show how much space will be freed up).
3. Confirm the action.

After cleaning the cache, some apps can take longer to load when they first run, which is normal, but don’t clear the cache for banking apps (like SberBank Online) and messengers with important data (like WhatsApp) unless you want to lose your chat history.

3. Remove unnecessary applications and junk files

The Mi 9 comes with Xiaomi apps pre-installed by default, many of which cannot be removed by standard means (e.g. Mi Video, Mi Music, GetApps) but can be turned off to keep them from taking up space and wasting resources.

To disable system applications:

1. Go to Settings → Applications → Application Management.
2. Select an unneeded app (such as Mi Pay).
3. Click “Disable” (if the button is inactive, the application is critical to the system).

To completely remove pre-installed applications, root or ADB rights will be required. If you are not an experienced user, it is better not to take risks - improper actions can lead to a "brick" (inoperability) of the device.

For junk files, they can be found manually or through third-party utilities, such as /storage/emulated/0/Download, which often accumulates downloaded files that are no longer needed, and /storage/emulated/0/DCIM/.thumbnails stores photo and video thumbnails that can be deleted.

4. Optimization of media files: photos, videos and music

Media files are the main memory eater, for example, one 4K video of 1 minute duration can weigh up to 400 MB, and a RAW photo can weigh up to 20-30 MB. In Mi 9 there are several ways to reduce their volume without loss of quality:

• 📸 Change the format of the photo: go to the camera → Settings → Photo format and select JPEG instead HEIF (If compatibility is more important than space saving).
• 🎥 Reduce video resolution: in the same camera settings, select Full HD (1080p) instead 4K.
• 🔄 Enable compression in Google Photos: Open the app, go to Settings → Backup and synchronization → Download quality and select “High Quality” (unlimited storage).

If you need to vacate the space urgently, but do not want to delete photos, use the cloud services:

• Yandex Drive – 10 GB free (convenient for backup).

⚠️ Attention: When you upload photos to Google Photos in Original Quality mode, they take up space in your Google account. If the quota ends, sync stops. Use High Quality for unlimited storage (with a slight loss of quality).

5.Use of built-in MIUI tools for deep cleaning

MIUI It has a few hidden memory optimization features that many people don't know about, and one of them is Deep Clean. → Memory. → Deep cleaning. This tool scans the system for the object:

• 🗑️ Unnecessary APK-Files (remains after installing applications).
• 📄 Empty folders and temporary files.
• 🔄 Duplicate files (e.g. screenshots with the same content).
• 📦 Remnants of Remote Applications.

Another useful tool is Background Cleanup (Settings → Battery & Performance → Background Cleanup) which closes the background processes that consume memory and battery power. However, don’t abuse this feature: some applications (like instant messengers) will stop sending notifications.

For advanced users, there is a “Developers” mode where you can limit background processes:

1. Activate Developer Mode: Settings → About Phone → MIUI version (click 7 times).
2. Back to Settings → Additionally. → For developers.
3. Find Process Limitation and select Process Maximum 2 (saves memory, but can lead to reboot applications).

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If after deep cleaning the smartphone began to work slower, restart it. MIUI sometimes incorrectly processes the vacant space without a reboot.

6. Third-party utilities: what can be used without risk?

If the built-in MIUI tools fail, you can use third-party apps, but not all utilities are safe — some can delete critical files or show false virus notifications.

Before using any utility, back up important data. For example, SD Maid has a Recycle Bin feature that allows you to recover accidentally deleted files within 7 days.

⚠️ Please note: Do not use applications such as Clean Master or DU Speed Booster. They aggressively clear cache, which leads to re-uploading of data and increased traffic.

7.Extreme measures: reset to factory settings

If all of the above methods fail, and the memory is still full of unknown files, the last option is factory reset, a radical method that deletes all of the data, including apps, photos, contacts and settings.

• 🔄 Make a backup copy through Settings → Additionally. → Backup and reset → Local backup.
• ☁️ Sync your contacts and calendar with your Google Account.
• 📎 Save important files to your PC or cloud.

For discharge:

1. Go to Settings → About the phone → Reset settings.
2. Select “Erase all data”.
3. Confirm the action (a password may be required).

Once reset, the Mi 9 will go back to the out-of-the-box state, and you'll have to reconfigure the device, but the memory will be completely cleaned of debris, and if the place ends quickly after that, the problem may be in the corrupted file system, in which case only the Fastboot flashing will help.

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Resetting to factory settings is the only way to remove viruses that masquerade as system files.If the smartphone has become slower after installing questionable apps, a reset may be necessary.

FAQ: Frequent questions about cleaning up Xiaomi Mi memory 9