How to increase memory on Xiaomi Redmi 9: from memory card to hidden MIUI settings

Why Redmi 9 is running out of memory and what to do about it

Owners of Xiaomi Redmi 9 sooner or later face the same problem: despite the stated 32/64/128 GB of internal memory, the free space melts like snow in the sun. High-resolution photos, messenger cache, app updates all eat up precious gigabytes. But the good news is that you can increase memory on Redmi 9 in several ways, and not all of them require the purchase of additional accessories.

In this article, we will discuss 7 working methods, from the banal addition of microSD to the little-known tricks with MIUI, which will help to free up space without losing data. It is important to understand that not all methods are equally effective: somewhere you will win 5-10 GB, and somewhere you will be able to add hundreds of gigabytes. We will also compare the pros and cons of each option so that you can choose the best one for your tasks.

Before you get to the instructions, check the current memory status: go to Settings → About Phone → Memory. If less than 10% of the total is free, the system is already starting to slow down, and it's time to act.

Method 1: Installing a microSD card is the most obvious, but not always the best option

The most common way to expand memory is to buy a microSD card. Redmi 9 supports cards with a capacity of up to 512 GB (officially stated up to 256 GB, but tests show work with 512 GB models from SanDisk or Samsung).

• 🔹 Speed: Cheap Class 10 cards will slow down when recording video 4K Or start a game. Choose a job that's comfortable. UHS-I U3 or A2.
• 🔹 Formatting: By default MIUI Offers to use the card as a portable storage (data is not encrypted) or as internal memory (encryption) + The second option eats up the app portability. ~10% of the card capacity for service files.
• 🔹 Compatibility: Some cards (especially no-name brands) may not be identified or cause errors.Before buying, check for reviews about a specific model for the Redmi 9.

How to install the map:

1. Turn off the phone and remove the tray for SIM-cards (use a paper clip from the set).
2. Place the microSD in a microSD slot (on Redmi 9 it’s a separate slot, not a hybrid one – you can use two SIM+ memory cards at the same time).
3. Turn on the phone. The system will suggest formatting the card - select the desired mode (portable or internal).

⚠️ Note: If you choose internal memory mode, the card cannot be retrieved without data loss, and some applications (such as WhatsApp or banking) may refuse to work with the transferred data.

Method 2: Transfer data to a memory card – what can be moved and what can’t be moved

Even if the card is installed, not all data can be transferred to it. MIUI move:

• 📷 Photo and video (via Gallery) → Albums. → Choose. → Move over).
• 🎵 Music and podcasts (most players have the option of saving on the SD).
• 📄 Documents and downloads (in Files, select a folder and click Transfer).
• 🎮 Some games (through Settings) → Annexes → Choose a game → Warehouse → Change).

Here's what you can't put on the map:

• 🚫 System applications (MIUI Launcher, Settings, Phone, etc.).
• 🚫 OS updates and security patches.
• 🚫 Cache of most social networks (Facebook, Instagram store it in internal memory).

For the portability of applications:

1. Open Settings → Applications → Application Management.
2. Select the application, click Storage.
3. If the Change option is active, move to SD. If not, the app does not support porting.

Method 3: Optimize internal memory – remove garbage without data loss

Before you spend money on a memory card, try to make room right now. MIUI has built-in cleaning tools:

1. Settings → About Phone → Memory → Cleaning – removes the cache of system and user applications.
2. Security → Cleanup – deeper verification (includes duplicate photos, large files, unused APKs).
3. Files → Categories → Multimedia / Documents → Large files – shows files over 10 MB.

It is also worth checking manually:

• 🗑️ Download folder – here accumulate outdated APK, archives and temporary files.
• 📥 Cash messengers: in Telegram go to Settings → Data and memory → Storage and clear the cache. WhatsApp is Settings. → Warehouse.
• 🎬 Offline content: YouTube, Netflix and Yandex Music store downloaded videos and tracks in internal memory.

For advanced users, there is a way to clean through ADB (requires a PC and enabled debugging over USB):

adb shell pm trim-caches 256m

This command compulsorily clears the cache of all applications, limiting its size to 256 MB.

⚠️ Note: Do not manually delete files in folders /data or /system — it could cause a failure. MIUI. Use only built-in tools or proven file managers like Solid Explorer.

💡

Enable Smart Cleanup in Settings → Battery and Performance → Cleanup – The system will automatically delete unnecessary files when the charge or memory level is low.

Method 4: Using Cloud Storage – When Physical Memory Is Lacking

If you’re actively using photos, videos or documents, cloud services can be an alternative to physical memory expansion. Redmi 9 preinstalled:

• 🌥️ Mi Cloud (5GB free, integrated into the MIUI). Automatically synchronizes contacts, notes and photos.
• 🌥️ Google Drive (15GB free) Suitable for documents and backups.
• 🌥️ Yandex Disk (10 GB free) is convenient for users from Russia thanks to the high download speed.

How to set up automatic uploading of photos in Google Photos:

1. Install the Google Photos app from the Play Market.
2. Open Settings → Backup and Synchronization.
3. Enable the option and select quality (High – unlimited space, Original – counts from Drive quota).

The benefits of clouds:

• ✅ Access to files from any device.
• ✅ Automatic backup.
• ✅ No risk of data loss when your phone breaks down.

Disadvantages:

• ❌ Requires a stable internet connection to access.
• ❌ Free fares are limited (5-15 GB).
• ❌ Confidential data is stored on third party servers.

Method 5: Connecting an external drive over OTG – a temporary solution for large files

If you need to free up space urgently (for example, to update the system), you can connect a flash drive or an external hard drive through the system. OTG-adapter. Redmi 9 supports USB OTG, but there are nuances:

• 🔌 File systems are supported FAT32, exFAT and NTFS (The latter may require a root right).
• 🔋 2.5′′ hard drives can be connected without additional power, 3.5′′ – only with an external unit.
• ⚡ Data transfer speed is limited by the interface USB 2.0 (up to 480 Mbps).

How to connect:

1. Buy it. OTG-adapter (Type-C) → USB-A).
2. Connect a flash drive or HDD to the adapter, then insert it into the phone.
3. Notifications will appear USB-Drive is connected – click to open files.
4. Transfer the data you need (such as video or backups) to an external medium.

⚠️ Warning: Do not remove the drive without safely shutting down! Go to Settings → Connected devices → USB and click Disable, otherwise you risk losing data.

Method 6: Hidden MIUI settings – how to free up memory without deleting files

MIUI has several hidden features that help you manage memory more efficiently, such as:

• 🔄 Limit background activity: Settings → Battery and performance → Battery management → Choice of applications → Limit background activity, which will reduce memory consumption per cache.
• 📦 Disable automatic application updates: Play Market → Settings → Auto-update of applications → Never.
• 🗃️ Use the function "Light" (Light mode): Settings → Special facilities → Lite mode: simplifies the interface and reduces memory load.

Another little-known trick is compressing data through Developer Options:

1. Activate Developer Mode: Settings → About Phone → MIUI version (click 7 times).
2. Back to Settings → Additionally. → For developers.
3. Find the option Don't keep activities and turn it on, which forcibly closes applications after they're released, freeing up memory.

For advanced users, there is a way to reassign default folders via ADB:

adb shell setprop persist.sys.storage_preload 1

This command forces the system to use external memory for temporary files (not working on all versions of MIUI).

💡

Developer mode allows you to fine-tune memory management, but improper changes can lead to unstable system operation.

Method 7: Alternative firmware is a radical method for power users

If you're willing to take risks, you can install custom firmware (like LineageOS or Pixel Experience).

• ✅ More flexible memory management (e.g., the ability to format adoptable storage without restrictions) MIUI).
• ✅ Lack of pre-installed software (bloat) that takes place.
• ✅ Regular security updates (relevant to older versions of Redmi 9).

There are, however, downsides:

• ❌ Loss of guarantee.
• ❌ The risk of “bricking” the phone in case of an error.
• ❌ Certain functions (e.g, IR-Game Turbo or Blaster may not work.

If you do, follow this algorithm:

1. Unlock the bootloader through the Mi Unlock Tool (requires waiting 7-14 days after the Mi Account is attached).
2. Install TWRP Recovery for Redmi 9 (the version must match the device’s codename, lancelot).
3. Download the right firmware (e.g. LineageOS 18.1) and GApps (if you need Google services).
4. Sweat through TWRP, having previously made a backup.

⚠️ Note: Redmi 9 with Mediatek Helio processor G80 Some custom firmware may not work properly with the camera module or sensors. XDA Developers.

FAQ: Frequent questions about increasing memory on Redmi 9