This wikiHow teaches how to install a custom ROM on your Android device, which changes the way the Android looks and feels when using it, and can breathe new life into an old device. Installing a custom ROM is an advanced procedure, and you risk rendering your Android device inoperable.

Part 1
Part 1 of 4:

Unlocking Your Bootloader

  1. 1
    Check if your manufacturer allows unlocking the bootloader. Depending on your Android device, you may be able to unlock the bootloader with the help of the manufacturer. Not all manufacturers allow this, and even if they do not all models may be supported.[1]
    • To quickly see which models your manufacturer allows to be unlocked, search "manufacturer unlock bootloader" (e.g. "HTC unlock bootloader"). This will typically display the manufacturer's bootloader website as the first result.
    • Nexus phones can always be unlocked.
  2. 2
    Check if your carrier allows unlocking the bootloader. Even if your device's manufacturer allows unlocking the bootloader and your device is supported, your carrier may still block it.
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  3. 3
    Understand the risks and limitations. When you unlock your bootloader, you typically void any warranty that is currently active. You also break the DRM on your device, which can cause problems with streaming music services. Unlocking your bootloader also disables Apple Pay as a security measure. Finally, throughout the entire process you run the risk of permanently disabling your device.
  4. 4
    Download the Android SDK tools you'll need. You'll need a few utilities on your computer in order to proceed with unlocking your bootloader.
    • Visit the Android developer website.
    • Scroll down to the "Get just the command line tools" section at the bottom of the page.
    • Click the link for the ZIP file for your operating system.
    • Place the ZIP file in a folder that you want the tools to be located in.
  5. 5
    Extract the ZIP file. Double-click the ZIP file after you've placed it in its folder and click the "Extract" option.
  6. 6
    Run Android SDK Manager. This will display a list of available SDK tools.
  7. 7
    Uncheck everything except Android SDK Platform-tools. This is the only software you'll need for unlocking your bootloader.
  8. 8
    Click Install.
  9. 9
    Download and install the USB drivers for device. You'll be able to find these on the support page of your device's manufacturer's website. Make sure to download the drivers that match your device's model.
  10. 10
    Connect your Android to your computer via USB.
  11. 11
    Open the platform-tools folder in the folder your SDK tools are in. This folder was created when you installed the SDK software.
  12. 12
    Hold Shift and right-click in the folder. Make sure you right-click in a blank spot.
  13. 13
    Click Open command window here. A Command Prompt window will appear already set to the correct location.
  14. 14
    Type adb devices and press Enter. You should see your device's serial number.
  15. 15
    Open your Android's Settings.
  16. 16
    Scroll to the bottom and tap About phone.
  17. 17
    Tap the Build Number entry seven times. This will enable the Developer Options menu.
  18. 18
    Return to Settings and tap Developer Options.
  19. 19
    Enable OEM unlocking (if present). Not all phones will display this option, and it is only necessary if it is there.
  20. 20
    Enable USB debugging. This allows you to send commands to your Android through ADB.
  21. 21
    Open your device manufacturer's unlock code procedure instructions. The following process will vary depending on your phone manufacturer. Be sure to follow the instructions they provide exactly. What follows here is a general guide.
  22. 22
    Reboot your device into the fastboot menu. The process for this will vary depending on your device, but generally you'll need to turn off your phone and then hold Power and Volume Down for 10 seconds.
  23. 23
    Type the unlock key retrieval command in ADB. This command is different for every manufacturer. For example, for HTC you would type fastboot oem get_identifier_token.
    • Make sure your Android device is still connected to your computer and the Command Prompt window is open from the platform-tools folder.
  24. 24
    Copy the device ID code. You'll see a long code appear on the screen, and it may be broken up into several lines. Click and drag to highlight the entire code. Press Ctrl+C to copy it.
  25. 25
    Submit your device ID code to the manufacturer. Use the bootloader unlock code request form to submit your code and request your unlock code. This can take a week or two, depending on the manufacturer.
  26. 26
    Run the command specified by your manufacturer. When you receive your unlock code, you'll be given the command to use to apply it to your device. This command varies depending on the manufacturer. Your Android will need to be connected to your computer and in fastboot mode.
    • For Nexus devices, run fastboot oem unlock, or fastboot flashing unlock for the Nexus 5X and newer.
    • The command for your manufacturer may be different. For example, HTC users would type fastboot oem unlocktoken Unlock_code.bin after placing the Unlock_code.bin file received from HTC into the ADB folder.
  27. 27
    Confirm that you want to unlock. You may be prompted by your phone to confirm the unlock.
  28. 28
    Type fastboot reboot on your computer. This command will reboot your device and exit fastboot mode.
  29. 29
    Look for the Bootloader Unlocked message. You'll see this message every time you turn on your device as a security measure. Make sure your device boots completely into the Android operating system as normal. You're now ready to install a custom recovery.
  30. 30
    Find and follow a device-specific guide if you can't unlock the bootloader. If your manufacturer or carrier will not allow you to unlock the bootloader, your only other option is to find and use an exploit to bypass it. This process is different for every phone model, and some phones simply cannot be unlocked at all.
    • The best place to get started are the XDA Forums. Find your phone model and look for any bootloader unlocks released by the community.
    • When performing an unlock using an exploit, be sure to follow every step in the XDA thread exactly, as the risk for bricking your device increases dramatically when not using official methods.
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Part 2
Part 2 of 4:

Installing a Custom Recovery

  1. 1
    Visit the TWRP website. This guide will cover installing TeamWinRecoveryProject (TWRP), one of the more popular recovery methods for Android ROMs. Another popular recovery is ClockworkMod Recovery (CWM). Both should work for installing most ROMs, though some ROMs will require a specific recovery environment.[2]
  2. 2
    Click the Devices tab.
  3. 3
    Verify that your device is supported. If your device is not on this list, try a different recovery environment like CWM.
    • Note that while your device might be supported, your carrier or region may not.
  4. 4
    Click the link for your device. This will display more details for your specific device.
  5. 5
    Click the Download link. This will download TWRP in IMG format to your computer.
  6. 6
    Copy the IMG file to your ADB folder. Place it in the same location as your ADB binary files. This will allow you to transfer it to your phone using ADB in the Command Prompt.
  7. 7
    Rename the file to twrp.img. This will make it easy to enter the name during the transfer.
  8. 8
    Type adb reboot bootloader in the Command Prompt. If you don't still have the Command Prompt open, hold Shift and right-click in the open platform-tools folder. Select "Open command window here."
  9. 9
    Type fastboot flash recovery twrp.img and press Enter. This will copy the TWRP image file to your Android device and replace your current recovery environment with it.
  10. 10
    Type fastboot reboot and press Enter.
  11. 11
    Press and hold the Volume Up and Power buttons as the device reboots. This will enter recovery mode in most devices.
    • Some devices may have a different button combination for entering recovery mode. Perform a web search for "model recovery mode."
  12. 12
    Enter your PIN if prompted. This will allow TWRP to access your encrypted device, which is essential for creating backups.
  13. 13
    Tap Backup. This will open the backup utility in TWRP. Creating a full backup of your system (Nandroid) will allow you to restore your device in case something goes wrong during the ROM installation.
  14. 14
    Select Boot, System, and Data. This will back up all of your essential system files and data.
  15. 15
    Swipe the bar to begin the backup. You'll see this at the bottom of the Backup screen. The backup process will likely take a while to complete, so let your Android device process.
  16. 16
    Return to the Backup menu and clear all of the options.
  17. 17
    Scroll to the bottom and select your special partition after Recovery. This will have different names depending on your device (PDS, EFS, WiMAX, etc.), and your device may not have anything listed here.
  18. 18
    Start another backup with your special partition selected. This will back up your IMEI information, which will be essential for restoring connectivity if you break something later.
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Part 3
Part 3 of 4:

Finding a ROM

  1. 1
    Visit the XDA forums. The XDA forums is the most popular Android development community on the internet, and you'll find virtually every available ROM here.
  2. 2
    Open the subforum for your device. You'll see popular devices listed on the main page, or you can use the search bar to find your specific model.
    • Make sure your model matches both your device and your carrier. The same device on two different carriers will have two different model numbers, and you'll need a ROM that matches your exact model.
  3. 3
    Scroll down to the ROMS, KERNELS, RECOVERIES, & OTHER DEVELOPMENT section. Each device on XDA will have a section that's dedicated to ROM development. You'll be able to find virtually any ROM of note for your device here.
  4. 4
    Find a ROM that looks interesting. The number of ROMs available for your device is heavily dependent on how popular it is. Some devices may only have one or two ROMs to choose from, while others may have dozens. Some devices don't have any ROMs available at all, but these are usually devices that don't have unlockable bootloaders.
    • Different ROMs can accomplish different things. Some ROMs are designed to be as barebones as possible for maximum performance, while others will add a bunch of features that aren't normally available on your device.
  5. 5
    Look for features and limitations. ROMs often add new features, but they also often have limitations that may not have been present on your original device. Make sure that you will be OK with the feature set of your new ROM.
  6. 6
    Carefully read the entire post for the ROM. Many ROMs will have special instructions that you'll need to follow during installation. It is imperative that you follow the author's instructions exactly, or you may encounter serious problems.
  7. 7
    Click the Download link for the ROM file. This will begin downloading the ROM file, usually in ZIP form. ROMs may be fairly large, and the file could take a while to download.
  8. 8
    Visit the GApps download site. This site allows you to download Googe's proprietary apps, like Gmail and the Play Store, since ROMs cannot legally include them.
  9. 9
    Select your device's configuration on the GApps site. You'll need to select your device's architecture (platform), operating system version, and the variant you want.
    • If you don't know your device's platform, you should be able to find it on the XDA Forum's device information page for your device.
    • Make sure the OS version matches the ROM you are installing, not your current OS version.
    • Most users can select Stock as the variant, which includes all of the default GApps.
  10. 10
    Click the Download button. This will begin downloading your selected GApps package. You should now have two ZIP files: your chosen ROM and the GApps file.
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Part 4
Part 4 of 4:

Installing the ROM

  1. 1
    Connect your Android to your computer. If it isn't already, you'll need to connect your Android to your computer via USB so that you can transfer the files onto the device's storage.
  2. 2
    Open your Android's storage on your computer. You can transfer the files to either your Android's internal storage, or to the SD card if you have one inserted.
  3. 3
    Copy the ROM and GApps ZIP files onto your Android. You can click and drag them to your device's storage. Make sure they are placed in the base directory for either the internal storage or the SD card (don't put them in folders).
  4. 4
    Disconnect your phone after transferring.
  5. 5
    Power off your Android device. You'll need to open Recovery mode, which you'll do from the powered-off state.
  6. 6
    Boot your Android into recovery mode. This process will vary depending on your device, so perform a web search if you aren't sure. Generally, you'll hold Power and Volume Down until the recovery menu appears. You'll know you're in the right place when you see TWRP.
  7. 7
    Tap Wipe. It is always recommended to wipe your device before installing a new ROM. This will delete all of the data on the device.
  8. 8
    Swipe the bar to perform a factory reset. The reset process will only take a few moments.
  9. 9
    Tap Install on the TWRP main menu.
  10. 10
    Scroll down and tap the ZIP file for your ROM. Make sure to start with the ROM, not the GApps file.
  11. 11
    Swipe the bar to start flashing. The ROM file will begin installing, which may take several minutes to complete.
  12. 12
    Return to the main menu after flashing and tap Install again. Now you'll be installing the GApps file
  13. 13
    Scroll down and tap the GApps ZIP file.
  14. 14
    Swipe the bar to begin the installation. The GApps installation will begin, which may take as long or longer than the ROM installation.
  15. 15
    Tap Wipe cache/dalvik and then swipe to confirm. This will clear the cache, which is necessary for starting the ROM the first time.
  16. 16
    Tap Reboot System. Your Android device will reboot, and if everything went smoothly you'll load your ROM's home screen environment.[3]
    • It may take a long time for your new ROM to boot. This should only happen the first time you boot it up.
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Community Q&A

  • Question
    I have a Huawei Ascend Y250. When I try to install Lollipop ROM, it shows an error, then aborts. What am I doing wrong?
    Community Answer
    Community Answer
    This can occur if your phone is not rooted. You can use Kingroot or other root apps.
  • Question
    What if I have already downloaded the ROM?
    Akash Sawarkar
    Akash Sawarkar
    Community Answer
    Switch off your phone and reboot it into recovery mode by pressing 'vol+' or 'vol-' and power button at the same time. If the Android logo appears on the screen, leave the buttons and you will see you are in recovery mode. In recovery mode, click on update from SD card / storage and select the downloaded ROM from your storage. It will start flashing the file and the device will be updated.
  • Question
    I'm about to buy AsusROG phone 2 and I want a custom ROM. But I am scared if my armory crate (a specific app on rog phones) will be deleted.
    Maarten van Heusden
    Maarten van Heusden
    Community Answer
    Armory crate will be removed if you install a custom rom. But you can just download the app from the play store again, so don't worry.
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Warnings

  • Performing a step incorrectly or out of order can permanently brick your device. Always read all of your device-specific instructions carefully before proceeding.
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About This Article

wikiHow Staff
Co-authored by:
wikiHow Staff Writer
This article was co-authored by wikiHow Staff. Our trained team of editors and researchers validate articles for accuracy and comprehensiveness. wikiHow's Content Management Team carefully monitors the work from our editorial staff to ensure that each article is backed by trusted research and meets our high quality standards. This article has been viewed 171,239 times.
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Co-authors: 11
Updated: May 28, 2021
Views: 171,239
Categories: Android
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