We can reset the OnePlus smartphone at any time to its factory settings or factory default settings, which irrevocably deletes all system data.

The following data is deleted or removed from the device:

Note: On the OnePlus smartphone, you can choose to leave the internal memory untouched, which means that only the system data and settings are deleted.

Android 10 | OxygenOS 10.0
Step 1:  Open the  Settings
Step 2:  Tap on  System
Step 3:  Tap on  Reset options
Step 4:  Tap on  Erase all data (factory reset)
Step 5:  Tap on  Erase all data
Step 6:  Tap on  Confirm
  1. Open the Settings
  2. Tap on System
  3. Tap on Reset options
  4. Tap on Erase all data (factory reset)
  5. Tap on Erase all data
  6. Tap on Confirm

OnePlus Instructions