Oppo F9 (F9 Pro) delete your Google & Gmail account

OS: Android 8.1 (Oreo); ColorOS 5.2

CPU: Octa-core (4x2.0 GHz Cortex-A73 & 4x2.0 GHz Cortex-A53)

Display: 6.3 inches, 97.4 cm²

Battery: Non-removable Li-Po 3500 mAh battery

Remove a Google account on Oppo F9 (F9 Pro)

If you are going to sell your old phone, you definitely need to delete your google account from your phone so that the new user cannot access your google profile and cause problems with google services.

What happens after deleting a Google account?
Emails, all data and content, including files and photos, will be deleted.
The phone user will not be able to access Google services that require an account (such as Gmail, Drive, Google Play or Calendar).
You will lose access to YouTube and Google Play subscriptions and content purchased through this account (for example, applications, games, music, TV shows).

How do I remove a Google account from my phone?
Go to Settings on your phone.
After that, select the menu item Accounts and backup.
Select Manage accounts to get a list of accounts on your device.