Unlocking the bootloader (bootloader) on Android 13 is a mandatory step for installing custom firmware, obtaining rootrights or restoring the “brick” after an unsuccessful update. However, the procedure has become more complicated than in previous versions: manufacturers have tightened security requirements, and Google has introduced additional system integrity checks through AVB 2.0 (Android Verified Boot). Without proper preparation, unlocking can lead to data loss, activation Factory Reset Protection (FRP) or even permanent blocking of the device.

In this guide we will look at:

  • 🔓 Official and unofficial unlocking methods for different brands (Xiaomi, Samsung, Google Pixel, OnePlus etc.).
  • ⚠️ Hidden riskswhich are not warned about on the forums (for example, blocking Widevine L1 for Netflix in 4K).
  • 🛠️ Step-by-step commands for fastboot and ADB with an explanation of each parameter.
  • 🔄 How to get everything backif unlocking led to problems (for example, an error DM-Verity).

Important: the procedure is different even for devices of the same brand, but with different chipsets (Qualcomm vs Mediatek). Therefore, before you start, check the model of your smartphone in Settings → About phone → Model and check the compatibility table below.

📊 Your Android smartphone 13 is from which manufacturer?
Xiaomi/Redmi/POCO
Samsung
Google Pixel
OnePlus
Realme/Oppo/Vivo
Other

1. Why is unlocking the bootloader on Android 13 more difficult than before?

In Android 12 and older, manufacturers began to actively use mechanisms to protect against unauthorized firmware changes. In Android 13 these measures have been tightened:

  • 🔒 AVB 2.0 (Android Verified Boot) - checks the integrity of boot, vendor and system partitions. When unlocking the bootloader, it may require additional keys.
  • 📱 OEM Unlock in gray —on some devices (for example, Samsung Galaxy S22+) the unlock option is hidden and requires activation through ADB.
  • 🚫 Lock FRP (Factory Reset Protection) —after unlocking it may request login and password from your Google account, even if you deleted it.
  • 🎮 Loss Widevine L1 —on many devices (for example, Xiaomi 12 Pro) after unlocking, the content protection driver is downgraded to L3, which blocks Netflix in 4K.

In addition, some brands (for example, Huawei and Honor) have completely banned bootloader unlocking for models released after 2021. For others (for example, Samsung), the procedure requires registration on the official website and waiting 7 days.

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Before unlocking, check whether your device supports Widevine L1 after modifications. To do this, install the application DRM Info from Google Play and see the current level of protection.

2. Preparing the device: what needs to be done BEFORE unlocking

Improper preparation is the main cause of “bricks”. Follow this checklist to avoid problems:

Enable USB debugging in Settings → About phone → Build number (press 7 times)

Install ADB and Fastboot drivers on PC (links in official Google documentation)

Download the original firmware for your model (in case of recovery)

Disable all PIN codes, pattern keys and fingerprints

Make a backup copy of your data (unlocking will reset the device!)

Check the battery charge (minimum 70%)

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Pay special attention to the point about backup. Unlocking the bootloader on Android 13 automatically launches fastboot flashing unlockwhich erases:

  • 📂 All user data (/data partition).
  • 📱 Application and system settings.
  • 🔑 Encryption keys (if the device is encrypted, the data will not be accessible even after unlocking).

For backup, use:

  • 🔄 ADB Backup (command adb backup -apk -obb -shared -all -f backup.ab).
  • ☁️ Cloud services (Google Drive, Mi Cloud, etc.), but keep in mind that some data (for example, SMS) are not synchronized automatically.
  • 💾 TWRP (if already installed), but on Android 13 many versions TWRP do not work due to changes in vendor section.
What happens if you don’t make a backup?

After unlocking the bootloader, the device will return to factory settings. You will lose:

- Photos and videos (if not saved in the cloud).

- Messages in instant messengers (Telegram, WhatsApp - if cloud backup was not enabled).

- Local notes, passwords from managers (for example, Keepass2Android).

- Settings for Wi-Fi and Bluetooth devices.

It is almost impossible to restore data after a reset, especially if it was turned on FBE (File-Based Encryption).

3. Step-by-step guide: how to unlock bootloader

The unlocking process depends on the manufacturer. Below is a universal instruction that is suitable for most devices on Android 13 (except Samsung and Huawei - there are separate sections for them).

Step 1: Enable developer modes and OEM Unlock

  1. Go to Settings → About phone.
  2. Find the item Number assembly and click on it 7 times until a notification appears You have become a developer!.
  3. Go back to the main settings and open System → For developers.
  4. Activate:
    • 🔧 USB debugging
    • 🔓 OEM Unlock (if the option is gray, see section 4).

Step 2: Connect the device to the PC and check the connection

Install Platform Tools from Google (includes adb and fastboot).Then:

adb devices

If the device is displayed in the list, enter:

adb reboot bootloader

Step 3: Unlock the bootloader via fastboot

In mode fastboot (on the device screen there will be an image of a robot) do:

fastboot flashing unlock

On some devices (for example, Google Pixel 7), you will need to confirm unlocking with the volume buttons, and then enter:

fastboot flashing unlock_critical

After successful unlocking, the device will automatically reboot and reset to factory settings.

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On devices with Qualcomm Snapdragon (for example, OnePlus 11) after unlocking, you may need to flash vbmeta with verification disabled AVB, otherwise the system will not boot.

4. Features of unlocking for different brands

Manufacturers make their own changes to the unlocking process. Below are the key differences for popular brands on Android 13.

Brand Unlocking requirements Features Link to official instructions
Xiaomi/Redmi/POCO Linking a Mi account to the device, waiting 7-168 hours Required Mi Unlock Tool. On new devices (for example, Xiaomi 13 Ultra) may be blocked after updating MIUI. Official website
Samsung Registration on Samsung Members, wait 7 days Unlocking is possible only for models s Exynos. On Snapdragon (for example, Galaxy S23 Ultra) the bootloader is locked at the hardware level. Official website
Google Pixel No waiting, but confirmation via fastboot On Pixel 7 Pro and newer unlocking resets Widevine L1 to L3. To restore, you need to flash the original boot.img. Official website
OnePlus Allowed without waiting, but the warranty is lost On OnePlus 11 unlocking requires disabling OEM Unlock in the settings before first linking of your Google account. OnePlus Forum

For Realme, Oppo and Vivo unlocking is officially prohibited on most models after 2020. However, there are unofficial methods through exploits (for example, EDL mode for Qualcomm), but they require deep technical knowledge and risk turning the device into a “brick.”

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On devices Samsung s Snapdragon (for example, Galaxy S22 Ultra for the USA) unlocking the bootloader is impossible without hardware modifications (for example, soldering resistors on the motherboard).

5. Common errors and how to fix them

Even if you follow the instructions exactly, errors may occur. Here are the most common ones and how to solve them:

Error: fastboot: error: Cannot generate random number for anti-replay protection

Cause: problems with drivers fastboot or conflict with the antivirus.

Solution:

  1. Disable the antivirus (for example Avast or Kaspersky).
  2. Update Platform Tools to the latest version.
  3. Try another USB port (preferably USB 2.0).

    4. Error: Device is locked. Cannot flash images

    Cause: the bootloader is not unlocked, but you are trying to flash the image.

    Solution: repeat the command fastboot flashing unlock and confirm unlocking on the device.

    Error: Invalid sparse file format at header

    Cause: damaged firmware file or incompatible version fastboot.

    Solution:

    • Download the firmware again (preferably from the official website).
    • Use fastboot from Platform Tools 33.0.3 or newer.
What to do if the device does not turn on after unlocking?

If after the command fastboot flashing unlock the device does not boot (hangs on the logo or blinks red LED), try:

1. Flash the original boot.img via fastboot flash boot boot.img.

2. Disable verification AVB command fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img.

3. If nothing helps, flash the full firmware via EDL (for Qualcomm) or Download Mode (for Samsung).

6. How to get everything back: re-locking the bootloader

If after unlocking you encounter problems (for example, banking applications stopped working or disappeared Widevine L1), the bootloader can block back. However, please note:

⚠️ Attention: Re-locking the bootloader on some devices (for example, Google Pixel 6 and newer) leads to activation Rollback ProtectionIf you were flashing an older firmware version, the device may be blocked forever.

To block the bootloader:

  1. Reboot the device into fastboot:
    2. adb reboot bootloader
  2. Run the blocking command:
    3. fastboot flashing lock
  3. Confirm the action on the device (with the volume button).

After blocking:

  • 🔄 The device will reset to factory settings again.
  • 🔒 Protection will return AVB, and custom firmware will stop loading.
  • 🎬 Widevine L1 may be restored (but not All devices). get

7. Alternatives to unlocking: when you don't need it

Unlocking the bootloader is not always a necessary step. In some cases you can do without it:

  • 🔧 root access without unlocking: On some devices (for example, Samsung Galaxy S21) can be obtained root through exploits (for example, DirtyPipe), but this is a temporary solution.
  • 📦 Installing Magisk without custom recovery: you can patch boot.img via Magisk and flash it without unlocking (but this will only work on some devices).
  • 🔄 Update via ADB Sideload: if you need to flash the official OTA update without unlocking, use:
    • adb sideload update.zip

However, these methods have limitations:

  • ❌ It is not possible to flash custom recovery (TWRP).
  • ❌ Some modules Magisk will not work.
  • ❌ Banking applications (for example, SberBank Online) may be blocked due to trigger SafetyNet.

FAQ: Frequently asked questions about unlocking the bootloader on Android 13

❓ Is it possible to unlock the bootloader without losing data?

No Command fastboot flashing unlock on Android 13 necessarily performs a reset to factory settings (userdata erased). unlocking Netflix stopped working in 4K? to unlocking.

❓ Why did Netflix stop working in 4K after unlocking?

This is due to the level being lowered Widevine to L3. To return L1, you need to:

  1. Lock the bootloader back (fastboot flashing lock).
  2. Flash the original boot.img and vbmeta.img.
  3. Reset to factory settings.

On some devices (for example, Xiaomi 12T) Widevine L1 does not recover even after these actions.

❓ How unlock the bootloader if the option OEM Unlock grey?

On some devices (for example, Samsung Galaxy A53 or OnePlus Nord 2T) the option OEM Unlock becomes active only after:

  • Linking a Google account and waiting 7 days.
  • Connecting to the Internet (the device must “call” the manufacturer’s servers).
  • Entering a command via ADB:
    • adb shell pm uninstall -k --user 0 com.android.phone

    ⚠️ The last method does not work on all devices and may disrupt the operation of telephony.

❓ Is it possible to unlock the bootloader on Huawei or Honor?

Officially - no. Since 2018 Huawei and Honor closed the bootloader unlocking app. Unofficial methods (for example, through DC-Unlocker or EDL) require:

  • Payment for access to the service (from $10 to $50).
  • Skills to work with Qualcomm 9008 Mode or Mediatek SP Flash Tool.
  • Willingness to risk turning the device into a "brick".

For new models (for example, Huawei P60 Pro or Honor Magic5) unlocking is impossible without hardware modifications.

❓ How to check if the bootloader is unlocked?

There are two ways:

  1. Reboot the device in fastboot and see the status:
    2. fastboot getvar unlocked

    If the answer unlocked: yes — the bootloader is unlocked.

  2. Install the application Bootloader Status from Google Play - it will show the status without rebooting.