If you are preparing your phone for resale, want to return it to its original state, get rid of any error or virus, instead of removing all applications and files manually, use the built-in tools for formatting.
Formatting through settings
To remove all user data from the device and return it to its original state, use the reset function to the factory settings. It is important that at this moment the smartphone is charged at least 30%. How to format a phone on Android:
Step 1 . Open the “Settings” menu and in the “Personal data” section select the “Restore and reset” item.
Step 2 . Click “Data Backup” and move the slider to “Enabled” to copy your personal information to the Gmail cloud storage and restore it on the next boot.
Step 3 . Configure other options in the Recovery and Reset menu. For example, select an account to back up data, enable or disable auto-recovery.
Tip : if you are preparing a device for resale and do not want to recover application data and passwords, then be sure to turn off data backup.
Step 4 . Click "Reset Settings" to format the Android and delete all user data from the internal memory of the device.
Step 5 . A new page will open, displaying detailed information about the process, as well as a list of accounts connected to the device. Select “Reset Phone Settings” to reset the memory.
Step 6 . Click the Erase All button to confirm the full formatting of user data.
After that, all files and applications will be deleted from the smartphone. When formatting is complete, configure the phone again, as when you first started.
Formatting via Recovery
Recovery or Hard Reset is resetting the smartphone to factory settings, which also includes full formatting. This method is used in cases where the device is locked or not included. How to clean the phone on Android completely:
Step 1 . Turn off the smartphone. If the screen does not work, remove and reinsert the battery inside. Run Recovery. To do this, hold down the “Power” and “Volume Down ” buttons for 5-10 seconds.
Tip : On each smartphone, Recovery runs differently. For example, a combination of buttons "Power" and "Increase the volume" , or "Home" and "Reduce the volume . " Detailed information on how to run Recovery, see the website of the manufacturer of the phone.
Step 3 . A protective screen appears with the image of Android. Simultaneously press the "Power" and "Volume Down" buttons (without holding) to go to Recovery.
Step 4 . A list of available commands appears. Use the physical buttons “Increase the volume” and “Reduce the volume” to move in the menu and select “wipe data / factory reset” . Press the "Power" button to format the device and carry all user data. Confirm the action if necessary.
The process can take from 5 to 15 minutes, depending on the size of the internal drive, the number of installed applications, downloaded files. Wait until the removal is complete, and then configure the smartphone as when it was first started.