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

The Xiaomi Redmi Note 9 is one of the most popular mid-range smartphones, but its internal memory (64 or 128 GB) is often a bottleneck. High-resolution photos, app cache, system updates and downloaded files quickly fill the storage, leaving the user with a choice: delete data or look for ways to expand. This article will help you understand how to effectively increase memory on the Redmi Note 9 – from basic methods to little-known tricks that work on MIUI 12/13/14.

We're going to look at not only the obvious solutions like microSD, but also the system settings that allow you to free up gigabytes of memory without losing important files. We're going to focus on the nuances of working with a memory card formatted as internal memory, which can both save the situation and create problems if you use it incorrectly, and we're going to figure out which applications are "eating" memory unnoticed and how to curb them.

Important: All methods have been tested on the Redmi Note 9 (M2003J15SC/M2003J15SS models), but most of them are applicable to other Note series devices (e.g. Note 9 Pro or Note 9S). If your smartphone runs Android 10/11/12 with a MIUI shell, the instructions will remain relevant.

1. Installation of a microSD memory card: nuances and pitfalls

The most obvious way to increase memory is to install a microSD card. Redmi Note 9 supports cards up to 512 GB (officially stated up to 256 GB, but tests show compatibility with 512 GB models of the A2 or UHS-I classes).

• 🔹 Hybrid Slot: If you use two SIM-I'll have to choose the second one. SIM, Or microSD, they won't work at the same time.
• 🔹 Formatting as internal memory: This mode allows you to combine a card with built-in storage, but has risks (more on this below).
• 🔹 Card speed: to record video in 4K or running applications from a card need a class UHS-I (U3) or A2. Cheap cards will slow down the system.

How to insert the card correctly:

1. Turn off your smartphone.
2. Use a paper clip to remove the tray (the hole on the right).
3. Install the microSD in the upper slot (if you use one SIM) or in the middle slot (if you refuse the second SIM).
4. Turn on the phone and wait for the card to be identified.

⚠️ Note: If the card is not recognized, check it on another device. Redmi Note 9 does not support exFAT cards out of the box - they need to be formatted in the format of the card. FAT32 or NTFS (But the second option may not be read).

2. Formatting microSD as internal memory: pros and cons

The Adoptable Storage mode allows you to combine a microSD card with built-in storage, but has serious limitations:

How to turn on this regime:

1. Go to Settings. → Warehouse.
2. Select your microSD card.
3. Click Format as internal memory (the device will warn you to erase all data!).
4. After formatting, select Transfer Data (optional).

⚠️ Note: If you delete the card formatted as internal memory without first disabling in the settings (Settings) → Warehouse → Map. SD → Disable), the system may freeze the next time it is turned on!

3.Inline memory optimization: what can be safely removed

Before you spend on a memory card, check which files take up space on the built-in storage. Often users do not suspect that the cache of applications, downloads and duplicate photos “eat” tens of gigabytes.

How to find and delete unnecessary files:

1. Go to Settings → Storage → Free up the space.
2. The system will analyze the files and suggest that you delete them: 🗑️ Cash apps (especially Facebook, Instagram, TikTok). 📁 Downloads (APK-files, old documents). 🎵 Unnecessary audio files (voice messages from messengers, music cache).

"Storage analysis."

Pay special attention to the folders:

• 📂 /DCIM/.thumbnails — Photo miniatures can be removed (restored automatically).
• 📂 /Android/data — This is where gigabytes of game cache are often stored (PUBG, Genshin Impact).
• 📂 /Download — Check for the old ones APK and duplicate.

4. Transfer of applications to a memory card: limitations and workarounds

Even if the card is formatted as internal memory, not all applications can be ported, system utilities (MIUI Launcher, Security) and some games (Call of Duty Mobile) block the transfer, but there are ways to get around this limitation:

Method 1: Manually through settings

1. Go to Settings → Applications → Application Management.
2. Select the application → Storage → Change → SD card.
3. Confirm the transfer (some data will remain in the internal memory).

Method 2: With ADB (for power users)

If the transfer button is inactive, you can force the application to move through Android Debug Bridge:

adb shell pm set-install-location 2

This command forces the system to install the applications on the map by default. Attention: some applications may not work as well after that!

Method 3: Application Managers

Utilities like AppMgr III or Link2SD (requires root) allow you to port even those programs that the system blocks, but they work unstable on MIUI - make a backup before using it!

⚠️ Note: Moving applications to a memory card can cause them to run slower, especially if the class card is a part of the system. U1 or Class 10 (not) A2). High Demand Games (Genshin Impact, PUBG) After transfer, they may be slowed down.

💡

Before transferring the application to the map, check its size in Settings → Apps → [Application] → Storage. If the OBb file (data) is larger than 1 GB, the transfer can take up to 10 minutes.

5. System garbage cleanup: hidden MIUI functions

MIUI has built-in memory cleanup tools that many users don't use, such as Deep Cleanup, which removes not only the cache, but also temporary system files that aren't visible in the standard menu.

How to start a deep cleaning:

1. Open the Security app (shield icon).
2. Go to the Cleanup. → Deep cleaning.
3. Select categories for scanning: 🗃️ Unnecessary files APK (leftovers after application installation). 📄 Empty folders (remain after deleting files). 🔍 Residual files (data from remote applications).

Clean up

Another useful tool is Memory Optimization in the same Security app, which analyzes background processes and suggests closing those that consume memory unnecessarily, for example, Facebook and Instagram often stay active in the background even if you're not using them.

For advanced users, there is the possibility of cleaning through the recovery mode (Recovery Mode):

1. Turn off the phone.
2. Press Power + Volume up until the MI logo appears.
3. Choose Wipe & Reset → Wipe Cache (not Wipe Data!).
4. Reset the device.

💡

Regular cleaning of cache via Security → Cleanup can free up to 3-5 GB of memory on Redmi Note 9 with active use of social networks and instant messengers.

6. Cloud storage and automatic synchronization

If physical memory expansion is not possible (for example, you use two or more of the same memory). SIM-The alternative is cloud services. Xiaomi offers its own solution - Mi Cloud, but its free tariff is limited to 5 GB:

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

1. Install the Google Photos app from the Play Market.
2. Open the settings (☰ → Settings → Backup and synchronization).
3. Enable Backup and Synchronization.
4. Choose quality: 📸 High quality (unlimited storage, photos compressed to 16 MP). 📸 Original quality (counted in 15 GB).

Once set up, all new photos will automatically upload to the cloud, and the old ones can be deleted from your phone via Google Photos → Recycle Bin → Clean.

⚠️ Before mass deleting photos from your phone, make sure they are successfully uploaded to the cloud! Check this in the web version of the service (photos.google.com) or through the application on another device.

7.Alternative methods: from root rights to memory chip replacement

If all of these things don't work, then radical measures are left, and they require technical skills and they can be insecure, but sometimes that's the only way out.

Method 1: Getting root rights

With root, you can:

• 🔧 Remove system applications (MIUI Often installs unnecessary services).
• 🔧 Transfer all applications to a memory card (even those that block the system).
• 🔧 Use the Xposed Framework to fine-tune memory.

How to get root on Redmi Note 9:

1. Unblock the bootloader through the official Xiaomi website (you need a Mi Account).
2. Install custom recovery (TWRP).
3. Sweep through Magisk to get root.

Method 2: Replacement of memory chip

It is technically possible to replace the built-in eMMC chip with a more capacious one, but this is:

• 💸 It costs almost like a new smartphone (from 5 000) ₽ work + chip-price).
• 🔧 Requires rations and specialized equipment.
• ⚠️ Risk of damage to the motherboard (the guarantee will be lost).

Method 3: Use OTG-storage

If you have USB-storage device (flash drive or external drive) SSD), You can connect it to the Redmi Note 9 via OTG-adapter (Type-C) → USB-A). The system recognizes it as a removable disk, so you can transfer files. OTG.

FAQ: Frequent questions about the memory increase on the Redmi Note 9