[GUIDE] How to unlock bootloader without erasing data

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ondraczsk

Member
Dec 19, 2015
31
44
Prague
For those, who don't know, there's how to unlock/lock bootloader without erasing data:

1. Turn off the phone
2.Hold power & volume down, keep the volume down button pressed!
3.Connect phone to PC, on PC fastboot type:
Code:
fastboot oem unlock
still keep the volume down pressed
4.Type:
Code:
fastboot reboot
when phone starts to reboot, release volume down(when black screen appear), for me, when it starts to reboot, I disconnect the phone too
5. Now phone should be unlocked without deleting data partition.
Tested, for me worked 100%, but you need to be careful, or you will lose data!

I hope it helps. :)
 
Last edited:

Danvitayan

Member
Dec 4, 2018
38
11
Thái bình
For those, who don't know, there's how to unlock/lock bootloader without erasing data:

1. Turn off the phone
2.Hold power & volume down, keep the volume down button pressed!
3.On PC fastboot type:
Code:
fastboot oem unlock
still keep the volume down pressed
4.Type:
Code:
fastboot reboot
when phone starts to reboot, release volume down(when black screen appear).
5. Now phone should be unlocked without deleting data partition.
Tested, for me worked 100%, but you need to be careful, or you will lose data!

I hope it helps. :)

it worked for me.thank you very much.
 
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marstonpear

Senior Member
May 15, 2016
492
190
you don't need to hold the vol down button all the time, you just need to hold it right after you enter the unlock/lock code ,then the phone will boot into fastboot again instead of erase menu
 
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cadenarcher

Member
Dec 11, 2018
13
4
eWCocwC.png

im stuck here
 

liboriof

Senior Member
Oct 28, 2013
59
28
Palermo
Thanks for this! Now, is there a way to install TWRP without losing data?
Yes, after unlocking the bootloader turn off the phone and reboot in fastboot mode.
On windows command type "fastboot boot twrp.img", where twrp.img is the name on recovery, and when the phone rebooting into TWRP in provvisoring mode, flash the zip file of the TWRP: in there mode the TWRP are permanent and your data are save.
Sorry for my poor english and hope that all are clar.
 
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ondraczsk

Member
Dec 19, 2015
31
44
Prague
Yes, after unlocking the bootloader turn off the phone and reboot in fastboot mode.
On windows command type "fastboot boot twrp.img", where twrp.img is the name on recovery, and when the phone rebooting into TWRP in provvisoring mode, flash the zip file of the TWRP: in there mode the TWRP are permanent and your data are save.
Sorry for my poor english and hope that all are clar.

yep
 
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chillout23

Senior Member
Feb 21, 2011
378
22
Somewhere around
Yes, after unlocking the bootloader turn off the phone and reboot in fastboot mode.
On windows command type "fastboot boot twrp.img", where twrp.img is the name on recovery, and when the phone rebooting into TWRP in provvisoring mode, flash the zip file of the TWRP: in there mode the TWRP are permanent and your data are save.
Sorry for my poor english and hope that all are clar.

Can you (or somebody else) tell me which twrp.img and which twrp.zip?
 

grufty47

Senior Member
Aug 5, 2018
77
18
Germany
For those, who don't know, there's how to unlock/lock bootloader without erasing data:

1. Turn off the phone
2.Hold power & volume down, keep the volume down button pressed!
3.Connect phone to PC, on PC fastboot type:
Code:
fastboot oem unlock
still keep the volume down pressed
4.Type:
Code:
fastboot reboot
when phone starts to reboot, release volume down(when black screen appear), for me, when it starts to reboot, I disconnect the phone too
5. Now phone should be unlocked without deleting data partition.
Tested, for me worked 100%, but you need to be careful, or you will lose data!

I hope it helps. :)

Thanks, yes it worked, but in Android 9 you need to grant/tick <OEM unlock> in settings/system/Advanced/developer options first.
 
Last edited:

rvr87

New member
Apr 23, 2017
1
0
Can anyone confirm that this works with Nexus 6P? (Sorry I know this is the Xiaomi area...)
 

zogajg26

Member
Jan 24, 2019
25
16
For those, who don't know, there's how to unlock/lock bootloader without erasing data:

1. Turn off the phone
2.Hold power & volume down, keep the volume down button pressed!
3.Connect phone to PC, on PC fastboot type:
Code:
fastboot oem unlock
still keep the volume down pressed
4.Type:
Code:
fastboot reboot
when phone starts to reboot, release volume down(when black screen appear), for me, when it starts to reboot, I disconnect the phone too
5. Now phone should be unlocked without deleting data partition.
Tested, for me worked 100%, but you need to be careful, or you will lose data!

I hope it helps. :)

Does this work on Mac os?
 

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  • 20
    For those, who don't know, there's how to unlock/lock bootloader without erasing data:

    1. Turn off the phone
    2.Hold power & volume down, keep the volume down button pressed!
    3.Connect phone to PC, on PC fastboot type:
    Code:
    fastboot oem unlock
    still keep the volume down pressed
    4.Type:
    Code:
    fastboot reboot
    when phone starts to reboot, release volume down(when black screen appear), for me, when it starts to reboot, I disconnect the phone too
    5. Now phone should be unlocked without deleting data partition.
    Tested, for me worked 100%, but you need to be careful, or you will lose data!

    I hope it helps. :)
    5
    Is this procedure still working after Android 10 update? I want to unlock bootloader but I would really prefer not to lose the data.

    Edit:

    Can someone give the full tested procedure please? There are reports in this thread of people having their data erased by following steps posted by OP. Not very helpful.

    Confirmed working on last available OTA (V11.0.5.0.QDLMIXM).

    I try to highlight the procedure with more detail as possible (but you should always take into account the risk to loose some data, so always backup first if you are concerned! I take no responsability and no procedure is risk free!)

    Prerequisites:
    - Android ADB/Fastboot Drivers installed on PC (for Windows)
    - Android Basic Tools (adb/fastboot) installed on PC (for Windows/Linux)
    There are several ways to get this tools installed (official Android SDK - several GB, custom minimal build with only adb/fastboot, official packages for android tools in some linux distros), and a lot of documentation everywhere.

    1) Enable the hidden "Developer Options" menu: Go to Settings -> Device Information -> Tap several times (10?) on the "Build number" line at the end of the page until you get a small notification on the bottom of the screen like "Now you are a Developer".

    2) Unlock the OEM settings: Go to Settings -> System -> (Expand the Advanced menu) -> Developer Options -> Enable the "Unlock OEM" setting.

    3) Swith off your device normally.

    4) Connect your phone to PC with a reliable USB cable.

    5) Switch on pressing PWR + VOLUME DOWN together you can stop pressing them when you see a "FASTBOOT" image on the screen.

    6) If using Windows a "New Device" popup might appear, wait for full driver installation.

    5) Open a Command Prompt/Terminal (Windows and Linux tested working). If you are using Windows or the Android SDK probably you will have to `cd` in the folder where you installed the fastboot/adb tools.

    6) From the terminal test that you can run fastboot and reach the device, by executing `fastboot devices -l` in the terminal. You should see as output something like `XXXXXXXXX fastboot` (first part would be different).

    ======= UNTIL HERE EVERYTHING WAS SAFE, THE NEXT IS THE MOST DANGEROUS STEP! ==========

    7) If the result from step 6 is okay, type `fastboot oem unlock` in the terminal but DO NOT PRESS ENTER YET (keep cats away from your keyboard!)!! Now you should start pressing "VOLUME DOWN" on the phone, pay attention to not disconnect accidentaly the usb cable, and WHILE KEEPING "VOLUME DOWN" PRESSED, hit "RETURN" on your keyboard to execute the command in the terminal. Your phone will reboot, keep "VOLUME DOWN" pressed.

    8) You will see again the FASTBOOT screen on your phone. [In principle here you could release the VOLUME DOWN button, but I keep it pressed just to be sure]. Enter in the terminal `fastboot reboot` and, as the mobile screen becomes black, release the VOLUME DOWN button. You will see a "Bootloader Unlocked" warning screen - nothing to be worried about, and then the device SHOULD complete boot normally.

    Note for Linux (maybe olso OSX) users: if you use something different than your distribution official packages for android tools, it's possible that you have to use `./fastboot` at the beginning of every terminal command instead of `fastboot`.
    5
    So the point is, to make enter the fastboot menu again after reboot?

    But contradiction between enter fasboot menu with the tutorial, its about to release the volume down button when after reboot instead keep pressing it to enter fastboot menu

    So please make me clear, id like to unlock without erased my data

    You can keep holding the vol down button, but that will not only make your thumb sore, but will also wipe your data (at least that's what happened on my device).
    Go into fastboot and connect the phone, type the code for unlocking, as soon as you hit enter, start holding the vol down button, you will go back to fastboot again. To make sure your data doesn't get wiped, type
    Code:
    fastboot reboot
    again and hold vol down as soon as you hit enter again. You will go into fastboot again. Then you can reboot your phone via fastboot to have your BL unlocked and your data saved.
    2
    you don't need to hold the vol down button all the time, you just need to hold it right after you enter the unlock/lock code ,then the phone will boot into fastboot again instead of erase menu
    1
    Confirmed working on last available OTA (V11.0.5.0.QDLMIXM).

    I try to highlight the procedure with more detail as possible (but you should always take into account the risk to loose some data, so always backup first if you are concerned! I take no responsability and no procedure is risk free!)

    Prerequisites:
    - Android ADB/Fastboot Drivers installed on PC (for Windows)
    - Android Basic Tools (adb/fastboot) installed on PC (for Windows/Linux)
    There are several ways to get this tools installed (official Android SDK - several GB, custom minimal build with only adb/fastboot, official packages for android tools in some linux distros), and a lot of documentation everywhere.

    1) Enable the hidden "Developer Options" menu: Go to Settings -> Device Information -> Tap several times (10?) on the "Build number" line at the end of the page until you get a small notification on the bottom of the screen like "Now you are a Developer".

    2) Unlock the OEM settings: Go to Settings -> System -> (Expand the Advanced menu) -> Developer Options -> Enable the "Unlock OEM" setting.

    3) Swith off your device normally.

    4) Connect your phone to PC with a reliable USB cable.

    5) Switch on pressing PWR + VOLUME DOWN together you can stop pressing them when you see a "FASTBOOT" image on the screen.

    6) If using Windows a "New Device" popup might appear, wait for full driver installation.

    5) Open a Command Prompt/Terminal (Windows and Linux tested working). If you are using Windows or the Android SDK probably you will have to `cd` in the folder where you installed the fastboot/adb tools.

    6) From the terminal test that you can run fastboot and reach the device, by executing `fastboot devices -l` in the terminal. You should see as output something like `XXXXXXXXX fastboot` (first part would be different).

    ======= UNTIL HERE EVERYTHING WAS SAFE, THE NEXT IS THE MOST DANGEROUS STEP! ==========

    7) If the result from step 6 is okay, type `fastboot oem unlock` in the terminal but DO NOT PRESS ENTER YET (keep cats away from your keyboard!)!! Now you should start pressing "VOLUME DOWN" on the phone, pay attention to not disconnect accidentaly the usb cable, and WHILE KEEPING "VOLUME DOWN" PRESSED, hit "RETURN" on your keyboard to execute the command in the terminal. Your phone will reboot, keep "VOLUME DOWN" pressed.

    8) You will see again the FASTBOOT screen on your phone. [In principle here you could release the VOLUME DOWN button, but I keep it pressed just to be sure]. Enter in the terminal `fastboot reboot` and, as the mobile screen becomes black, release the VOLUME DOWN button. You will see a "Bootloader Unlocked" warning screen - nothing to be worried about, and then the device SHOULD complete boot normally.

    Note for Linux (maybe olso OSX) users: if you use something different than your distribution official packages for android tools, it's possible that you have to use `./fastboot` at the beginning of every terminal command instead of `fastboot`.


    Thank you. I appreciate this!