Formatting a memory card on Android: 5 methods and safety tips

Cards memory microSD is an indispensable accessory for owners of smartphones with Android, especially if the built-in memory is sorely lacking. However, over time, the drive begins to “glitch”: files cannot be opened, the writing speed drops, and the system produces errors like “The SD card is damaged”. In 90% of cases, the problem is solved by simple formatting - but how to do it correctly so as not to lose important data and not completely damage the card?

In this article we will analyze all working formatting methods - from standard Android tools to advanced methods via Recovery or a computer. You will learn which file system to choose (FAT32, exFAT or NTFS), how to avoid common errors and what to do if the card refuses to format. And if you are afraid of losing data, there is a section at the end about restoring it.

When do you need to format a memory card?

Format is not just clearing files, but completely rewriting the file system of the drive. It is required in several cases:

• 📱 Card not detected smartphone or displays a notification “Empty SD card»/«Damaged card».
• 🐢 Speed reading/writing has dropped significantly (photos are saved for minutes, videos freeze).
• 🔄 You want change file system (for example, from FAT32 to exFAT for files >4 GB).
• 🦠 The card is infected with viruses that cannot be removed by the antivirus.
• 🔄 You plan to use it in another device (for example, in GoPro or Nintendo Switch).

Important: if the card is physically damaged (cracks, chips, contacts have oxidized), formatting will not help - it needs to be replaced. Also, you should not format the drive “just in case”: each rewrite cycle reduces its service life.

⚠️ Attention: some manufacturers (for example, SanDisk or Samsung) produce cards with proprietary diagnostic software. If your card “died” after updating the phone’s firmware, first check it through the official brand utility.

Method 1: Formatting through Android settings

The easiest method is to use the built-in tools of the system. It is suitable for most devices on Android 6.0 and later (including Samsung, Xiaomi, Realme etc.).

Instructions:

1. Open Settings → Storage (or Memory).
2. Find the section "SD card" or "External storage" and tap on it.
3. In the menu with card information, select "Format" or "Clear».
4. Confirm the action (you may need to enter a password or pattern).

On some firmware (for example, MIUI or ColorOS) path may differ:

• 🔧 Settings → Advanced → Memory → SD card → Format as internal (if you need to expand the phone memory).
• 📁 Settings → Storage → Storage → SD card → Erase and format.

Save important files to another device

Check the battery charge (at least 30%)

Close all applications that use the card

Remove the card if the phone “does not see it” and insert it back-->

If the formatting option is inactive, it means:

• 🔒 The card is used as internal storage (it cannot be formatted without resetting the phone).
• 🛠️ The drive is write protected (check physical switch Lock on the adapter).
• 🦠 The card is damaged (try other methods from this article).

Method 2: Formatting as internal storage

If you want to use microSD as part The main memory of the phone (for installing applications), it needs to be formatted in a special way. This method is called Adoptable Storage and works on Android 6.0–9.0. On new versions (Android 10+), the function may be disabled by the manufacturer.

How to do this:

1. Insert the card into the smartphone and wait for it to be detected.
2. Go to Settings → Storage → SD card.
3. Tap on the three dots (⋮) in the upper corner and select "Storage settings».
4. Click "Format as internal" and confirm.
5. Wait for completion (may take up to 10 minutes).

After that:

• ✅ The card will be encrypted and linked to your device.
• ⚠️ It cannot be read on another phone or PC without formatting.
• 📱 Applications can be installed on it (but the speed may drop).

⚠️ Attention: if you are selling a phone, first format the card as Portable v the same settings, otherwise the new owner will not be able to use it.

For photos and videos

For installing applications

For backups

Another option -->

Method 3: Formatting via Recovery Mode

If Android does not see the card or gives errors when formatting, try doing this via recovery mode (Recovery). This method is suitable for devices with root access or custom recovery (for example, TWRP).

Instructions for TWRP:

1. Turn off the phone and hold down the button combination to input to Recovery (usually Power + Volume up).
2. In the menu TWRP select "Wipe» → «Advanced Wipe».
3. Tick "External SD" (or "Micro SD Card»).
4. Swipe to confirm (Swipe to Wipe).
5. After completion, press "Reboot System».

For standard Stock Recovery:

1. Go to Recovery (the combination of buttons depends on the model).
2. Select “Wipe data/factory reset" (on some devices there is a separate item for SD).
3. Confirm the action.

If there is no option in recovery to format the card, use ADB:

adb shell
sm partition disk:179,64 private

(Replace 179,64 with the current parameters of your card - they can be found through the command ls /dev/block/mmcblk1.)

Method 4: Formatting via computer (Windows/macOS/Linux)

If the phone refuses to format the card, connect it to the computer. This is the most reliable method, since the PC offers more options (selecting a file system, low-level formatting, etc.).

For Windows:

1. Insert the card into the card reader and connect to the PC.
2. Open "This computer» (My computer), find the removable disk.
3. Right click → "Format».
4. Select file system:
   • FAT32 — compatible with all devices (max. file 4 GB).
   • exFAT — for files >4 GB (modern phones support).
   • NTFS —only if the card will be used only on a PC.

For macOS:

1. Open "Disk Utility» (Applications → Utilities).
2. Select the card in the list on the left.
3. Click "Erase" and specify the format MS-DOS (FAT) or ExFAT.
4. Confirm the action.

For Linux (via GParted or terminal):

sudo mkfs.vfat /dev/sdX1

(Replace sdX1 with the current section of the card - you can find it with the command lsblk.)

File system	Max. file size	Compatibility	When to use
FAT32	4 GB	All devices	For photos, music, old phones
exFAT	16 EB	Android 6.0+, Windows, macOS	For 4K video, large games
NTFS	16 EB	PC, some Android with root	Only for PC work

💡

If Windows says "Windows cannot complete formatting", use utility SD Formatter from SD Association (official tool for memory cards). It supports low-level formatting and often saves “broken” drives.

Method 5: Low-level formatting (for experienced users)

If the card is “dead” and cannot be formatted using standard methods, try low-level formatting. It completely overwrites all sectors of the drive, restoring its functionality. Attention: this method deletes data beyond recovery!

Tools for low-level formatting formatting:

• 🖥️ HDD Low Level Format Tool (Windows) - supports microSD via a card reader.
• 🐧 dd (Linux/macOS) - command for complete rewriting:

  sudo dd if=/dev/zero of=/dev/sdX bs=1M status=progress

  (Replace sdX with your disk! An error here will lead to data loss on another drive.)

• 📱 SD Card Formatter (official utility from the SD Association) - soft low-level formatting.

After low-level cleaning, the card must be formatted again (see Method 4).

⚠️ Attention: low-level formatting reduces the life of the card. Use it only if other methods have not helped. Also note that some card controllers block this operation - in this case, the drive will have to be replaced.

What to do if the card cannot be formatted?

If none of the methods worked, the problem may be:

• 🔌 Physical malfunction (the contacts are oxidized, the controller is broken).
• 🔒 Write protection (check the switch Lock on the adapter).
• 🦠 Virus, blocking access (scan the card on a PC with an antivirus).
• 📱 Incompatibility with the phone (some budget smartphones do not support cards >128 GB).

Try these steps:

1. Connect the card to another device (PC, another phone, camera).
2. Check it using the utility CrystalDiskInfo (Windows) or Disk Utility (macOS) for errors.
3. If the card is detected, but not formatted, use diskpart c Windows:

   diskpart
   list disk
   select disk X (where X is your card number)
   clean
   create partition primary
   format fs=fat32 quick

4. If all else fails, the card is dead. Buy a new one (we recommend brands SanDisk Extreme, Samsung EVO or Kingston Canvas).

How to recover data after formatting?

If you formatted the card by mistake, do not panic! With quick formatting (option Quick Format), the data is not deleted immediately - it is simply marked as available for overwriting. The chances of recovery are high if:

• 🕒 Little time has passed since formatting.
• 📵 Nothing was written to the card.
• 💾 The card is not physically damaged.

Recovery apps:

Instructions for recovery from using PhotoRec:

1. Connect the card to the PC.
2. Download PhotoRec (included in the package TestDisk).
3. Run the app through the terminal (Windows: photorec_win.exe).
4. Select the disk with the memory card.
5. Specify the file system (FAT/NTFS/exFAT).
6. Select a folder to save the recovered files (not to the card itself!).
7. Wait until the scan is completed.

Important: recovered files may be renamed or damaged. Photos/videos are usually recovered best, and documents (for example .docx) - worse.

FAQ: Frequently asked questions about formatting memory cards

adb shell sm set-force-adoptable true