Tap Backup & Reset .
The phone will reboot and erase everything. This takes about 2-5 minutes. Use this method if you forgot your screen lock, password, or the phone is stuck on the logo screen.
Phone is stuck in a boot loop after reset.
This is Factory Reset Protection . It's a security feature. You must enter the previous Google account (email and password) that was used on the phone before the reset. If you don't know it, you cannot bypass this legally. How to Hard Reset HUAWEI L21 P9 Lite
If you have a screen lock (PIN, pattern, or password), enter it.
A hard reset will erase ALL data on your phone, including contacts, photos, apps, messages, and accounts. It will return the phone to the exact state it was in when you first bought it. Back up your data before proceeding.
Scroll down and tap Advanced Settings (on some EMUI versions, look for System ). Tap Backup & Reset
Open the Settings app.
There are two methods to hard reset a Huawei P9 Lite (L21): This is the easiest method if you can still unlock your phone.
If your Huawei P9 Lite L21 has a Google account on it, you must know that password after the reset, or the phone will lock itself. This is an anti-theft feature. Use this method if you forgot your screen
Tap RESET PHONE again to confirm.
Read the warning list. Tap RESET PHONE .
Tap Factory data reset .