Tap Backup & Reset .
If you have a screen lock (PIN, pattern, or password), enter it.
Tap Factory data reset .
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. How to Hard Reset HUAWEI L21 P9 Lite
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.
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.
Read the warning list. Tap RESET PHONE . Tap Backup & Reset
Repeat Method 2. After selecting "Wipe data/factory reset," also select "Wipe cache partition" (this is safe and won't delete personal data). Then reboot. Final Summary Table | Method | When to use | Buttons required | |--------|-------------|------------------| | Settings | Phone works normally | None (touchscreen) | | Recovery Mode | Phone frozen, locked, or won't boot | Vol Up + Vol Down + Power |
Tap RESET PHONE again to confirm.
Scroll down and tap Advanced Settings (on some EMUI versions, look for System ). A hard reset will erase ALL data on
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.