A factory reset will restore your phone to the settings that were configured in the factory. All of your personal data from the internal device storage, including account information, the system and application settings, and any downloaded applications will be erased.
Important: Back up your personal data before performing a factory reset.
Backing up personal settings
1. On the Settings screen, tap System > Backup.
2. Slide the Back up to Google Drive (or Google One requires a subscription) switch to the right.
Restoring Factory data
1. On the Settings screen, tap System > Advanced > Reset options > Erase all data (factory reset).
2. When prompted, tap Erase all data, and then tap Erase all data. The device will reset to the original factory settings, and then restart.
Note: Resetting your device does not erase any system software updates that have been downloaded or any files on a microSD card, such as music or photos.