TWRP is a name that many are familiar with, as your Android device can use it to install any custom file of your choice. You can create a NANDroid backup to protect your data, or use Magisk for full root access. In fact, TWRP is often seen as the gateway to modifying your system for a unique user experience.
TWRP lets you control the software of your phone much better. This is something all power users should consider when dealing with root-related system mods. Installing TWRP overwrites the restoration of your data. However, the benefits of custom recovery are so far above average that it pays off in the long run.
- Windows, Mac, or Linux computer
- USB data cable
Before you begin installing unofficial image files on your system, such as TWRP can, the bootloader must be unlocked. You will find that this is the case with all Android phones when you first enter the rooting and modding scene. It is necessary to make changes to the system. If you need to do this, click on the following link.
Once the boot loader is unlocked, you'll need to get the TWRP image for your particular Pixel 3a model next download. Since TWRP is still working for Pixel 3a, first use these unofficial images of the XDA Developer ZVNexus.
Download the TWRP image file from the top for Pixel 3a or 3a XL, and then rename it to twrp (or twrp.img if file extensions are displayed on your computer) to simplify the installation ,
Note that TWRP support for Android Q is not available So if you plan to use TWRP on your Pixel 3a, you will need to run Android 9 Pie. Official support for Android Q should be expected sometime in August 2019. Search here for an update.
Step 3: Booting in Fastboot Mode
Now you have the base image file required to boot your Pixel 3a into TWRP, but your phone is not ready to accept the Fastboot command is required to get the ball rolling. Before you can start, you need to put your phone into fastboot mode so that it can receive commands from your computer.
Long press on the power button to bring up the network menu Tap the "Turn off" option to turn off the phone completely. After turning off, press and hold the power key and the volume key at the same time until the fastboot mode screen is displayed. Now connect your phone to your computer with a USB cable and leave it for the next steps as follows.
Step 4: Install ADB & Fastboot on Your Computer  Now it's time to install the framework on your computer so you can use this TWRP image File to your phone. You need Google's standalone SDK Platform Tools package to get the necessary ADB and fastboot commands. Everything is contained in a neat folder, so things stay simple – no confusing drivers need to be installed:
Step 5: Open a Command Window in Platform Tools  Now, both your phone and computer can accept all the fastboot commands required to install your own custom files, such as: For example, the TWRP image. Your phone should still be in the main screen of the Fastboot menu at this time, so you must now open a command window in the platform-tools folder on your computer. Click on the following link to start the setup and you're almost done.
Finally, it's time to create this TWRP image file (twrp.img) that you previously downloaded and transfer it to the platform-tools folder on your computer. Once the file is in your Platform Tools folder, you can run a quick start command that launches TWRP.
Using a Command Window Open the platform-tools folder, type the following command and press Enter.
fastboot boot twrp.img
Note: Mac and Linux users will most likely need to add a period and a slash before entering any of the commands listed here (for example, ./fastbootboot twrp.img) ,
When you press Enter, your phone will respond immediately and temporarily start the TWRP Main Menu. From here you can immerse yourself in the process of installing other mod files on your system, eg. Magisk or any custom kernel you might want to try. For now, you'll need to run this method each time until you've made further progress on TWRP for Pixel 3a.
For A / B partition devices such as Pixel 3a: Normally, you will temporarily boot TWRP and then install a permanent version. However, currently you can not permanently install the Pixel 3a on your phone. This means that you need to establish a connection between the computer and the phone each time to start TWRP whenever you need it.
TWRP progress on Pixel 3a is still ongoing. Therefore, I will update the instructions here, if possible, to permanently install TWRP on the system partition. The good news is that you still have full access to all functions, which is fantastic, but you just do not have the benefit of being able to flash files on the go. Nothing to be annoyed about!